Game of Thrones begins....

[viper37]

I wonder why she didn't take all 3 dragons with her...

To protect the Castle in case Euron would attempt to attack.  Virtually no army there, the possibility of leaks, she didn't want to suffer a repeat of her previous departure from her forces.

  And those ballistas - I was reminded of the wind lances in The Battle of the Five Armies - I'm guessing the walls of King's Landing have more than a few mounted on them.

Now that Dani knows about them though, she might be more careful.

[viper37]

Ok, that clears it up for me:
"All the gold's safely through the gates of King's Landing."

So it is there.

[Habbaku]

All the gold except Bronn's precious bag. 

[Razgovory]

Nobody liked my horse joke.

[grumbler]

You can easily fill the blanks.  Jon recommends against attacking and burning a city filled with civilians, trapped in the nobles' fights.  Ergo, she is not going to attack a city.

The fleet that transported Grey Worm to Casterly rock lies at the bottom of the sea.  He has to cross on foot all of the continent to reach Dani and Missandei, with a Lannister army in nominal control of the area, at best, with people who look at the unsullied as filthy foreigners and really won't go out of their way to help them.

Dani promises Missandei that Grey Worm will be back.  It follows she has a plan:
1) attack Kings Landing, burn everything including the Queen
2) Abandon Dragonstone, march with Jon to the North, link up with his armies, march south to free Grey Worm, defend against the White Walkers together, worry about Cersei later.
3) attack the troops that just defeated the Tyrell.

#1, is what she wants to do at first, and his dismissive of Tyrion, starting to suspect him because he's a Lannister (by name, at least)
#2 would go contrary to all her instincts and would represent a severe blow to her as she leaves an ennemy army sorta of intact in the field, ready to strike at the North while they're either still in the South or busy fighting White Walkers.  Besides, Dragonstone is her birth place, even if she does not remember it, it holds sentimental value to her and it would be a huge blow to moral.
#3 is quite logical and the show leads you toward this: the column is slow, Jamie sends Bronn to motivate the harvesters, there's a slow gold convoy just leaving the Tyrell's home and the army is exhausted after a fight with the Tyrells and they likely sustained moderate casualties and still have a lot of wounded among their ranks.  You don't want to give the injured time to heal and rejoin their companies, you want them to be demoralized, at the very least.

These are only three of many options she could have taken.  Your imagination is much to limited, I guess, to do anything but predict what she might do except in hindsight.  Your argument that having Jon suggest the option she took would "ruin the show" is totally unsupported and silly.

What else could she have done, besides carry out the plan Jon opposed, or suddenly appear out of nowhere in the supply train battle?
(1) Have the Unsullied march back to Storm's End, or down to Highgarden (to reinforce her alliance there). 
(2) escort the Unsullied with a dragon
(3) sail her remaining fleet, accompanied by a dragon, to pick up the Unsullied at Casterly Rock.
(4) take Drogon and go negotiate with the Dornish for an attack on King's landing, just as she had planned.  The Dornish could pick up whatever Highgarden forces were left on the way.

All of these things were possible.  She asked for advice, and got almost nothing useful.  Having Jon provide useful advice would have advanced the whole plot of Dani coming to trust him.  It was a missed opportunity.

There's enough shown on screen to realize the convoy will be attacked by Dani and her dragons.  Plus, Tyrion says they have enough ships to move the Dothrakis to Kings Landing.  That means they can move the Dothrakis and the dragons.

This is all post hoc rationalization.  Of course we know dani will attack the army when the scene shifts to the army.  They'd not have gone to the bother of showing the army just marching back to King's Landing.

Although they could still have been misleading us all along, it would be very strange for all these elements to amount to nothing and having Jamie and Bronn report safely to King's Landing, gold&harvest intact while Dani was still brooding in Dragonstone.

Thank you, Captain obvious! 

My point is that they could have advanced the plot very effectively, and made the attack not such a random event, had Jon suggested it back at Dragonstone.

Inaction is not really in her nature, we have seen her very patient, playing the long game, but she has a temper, and she did grow some nerves since S01E01.

Duh! 

Sansa is concerned about the long winter, a winter that can last 10 years.  Jamie is concerned about supplies because he needs to move his army around, Dorne may be knocked out but not defeated and he wants to invade the North at some point, where forage will be low.
Dani is sitting on a rock island with no agricultural fields.

You can't have my point!  Everyone knows that this will be a long winter.  The maesters have said so, and they sent ravens everywhere (remember the scene of hundreds of them leaving the Oldtown tower?), so everyone is concerned with food.  It made no sense for Dani to burn all that food deliberately when she could just have burned out the troops escorting it and captured all that food.

The successors to House Martell could be very happy to have gained power now du to Ellaria's interference.

Yes, and they will still hate the Lannsters and want revenge.  They just wouldn't need to bother avenging themselves on Ellaria, because Cersei has already done that.  Ellaria would be no asset to Dani.

But they could also be tempted to declare neutrality, let everyone duke it out and then attack the Lannisters if they ain't defeated.

If you read the books, and watch the show, and still think the Dornish are the type to just sit back and hope someone else gets their vengeance for them, all I can say is:  you are not paying attention.

I have not seen the preview, but I find this a viable theory given what we know.

You should watch that second trailer for the season (I think it was issued at ComicCon.  It has lots of clues as to what Jon is going to be up to, but doesn't really spoil anything other than the fact that he goes beyond the Wall with the Brotherhood Without Banners (or, at least, with Beric Dondarrion, Sandor Clegane, and Thoros of Myr).

[viper37]

(1) Have the Unsullied march back to Storm's End, or down to Highgarden (to reinforce her alliance there). 

Like Jaimie said in Ep#3, they are in hostile territory with no supplies.  Attempting such a march would remind of a certain templar expedition against Saladin.  Doom to failure.

(2) escort the Unsullied with a dragon

Dragons can't fly a thousand miles without resting and feeding, that's been pretty much established last season and besides they ain't invincible if she encounters an army alone, or he might just decide to take a nap and Dani would be left alone, and exposed, just like 2 seasons ago.

(3) sail her remaining fleet, accompanied by a dragon, to pick up the Unsullied at Casterly Rock.

Again, way too risky.  The ennemy controls the seas and could easily sink half the fleet before one of the dragons manages to sink a few boats.  They are strong against ships standing relatively still attacking a harbor, or disembarking troops.  If Euron attacks again at night, or in the fog, surprising them, they could sing the ship and strand Dani.

(4) take Drogon and go negotiate with the Dornish for an attack on King's landing, just as she had planned.  The Dornish could pick up whatever Highgarden forces were left on the way.

Not knowing who's in charge of the Dornish, how long this will take, and they know Dani isn't in a position of strenght anymore, despite the dragons, this result is uncertain and still leaves the Lannister gather a lot of supplies and march their army back to KL unhurt.

All of these things were possible.  She asked for advice, and got almost nothing useful.  Having Jon provide useful advice would have advanced the whole plot of Dani coming to trust him.  It was a missed opportunity.

He gave a very useful advice: be as you always were, be the Queen your people have followed so far, don't be another Mad King or a Cersei, willing to sacrifice anyone for what you think is your birthright.  Like Missandei said, they don't follow her because she's related to a foreign king they never knew.  If she stands a chance of ruling peacefully, she has to prove to everyone she's different.  Otherwise, it will be burning after burning.

This is all post hoc rationalization.  Of course we know dani will attack the army when the scene shifts to the army.  They'd not have gone to the bother of showing the army just marching back to King's Landing.

Like I said, it was pretty evident the moment we saw the convoy and the army exposed that it would be attacked.  Not exactly post hoc, I saw it as it happenned, that's all.  Not being a US president, I usually don't tweet about everything while watching tv

My point is that they could have advanced the plot very effectively, and made the attack not such a random event, had Jon suggested it back at Dragonstone.

again, that would be taking the viewer by the hand and spelling everything/writing it in big characters so everyone could understand without thinking. That ruins a story for me when it is done in television/cinema.

You can't have my point!  Everyone knows that this will be a long winter.  The maesters have said so, and they sent ravens everywhere (remember the scene of hundreds of them leaving the Oldtown tower?), so everyone is concerned with food.

Ah, right, I forgot that scene.

It made no sense for Dani to burn all that food deliberately when she could just have burned out the troops escorting it and captured all that food.

Well, if there's no more Lannister to feed, you need less food...

Yes, and they will still hate the Lannsters and want revenge.  They just wouldn't need to bother avenging themselves on Ellaria, because Cersei has already done that.  Ellaria would be no asset to Dani.

I don't know enough of Dorne's political situation to comment.  But she might want the Greyjoy sister back, since she is a legitimate heir.

If you read the books, and watch the show, and still think the Dornish are the type to just sit back and hope someone else gets their vengeance for them, all I can say is:  you are not paying attention.

When Aegon conquered the kingdoms, they didn't rush to anyone defence. They sat out the war and waited for the Targaryans to attack - unsucessfully. They just waited it out until the Targaryans offered them an equal partnership: a marriage.

As for vengeance, twice they tried, twice they failed.  Why would they again rush to it?  They're like Will. E Coyote and get stuck on a single, unatainable target instead of trying something else?  They have shown to be patient.  They waited, what, 20 years to try to take revenge for the death of their sister?  And in the books, Doran Martell has been planning his revenge since the day his sister died and he had concluded a pact to marry one of his girls to Viscerion.  And didn't he send a nephew to offer marriage to Daenerys?

The books taught me these guys can be patient when the odds seem unsurmountable.  And again, the situation is unclear: who's ruling there?  Are they related to the Martells or where they all purged? Oberyn only had daughters and they're all dead, and none of them had kids. Whomever is left in charge maybe just doesn't care about the death of Elia Martell 20 years ago.  Althout we lack sufficient information, Dani does say she is without allies now, so it seems the Dornish can't be counted on for the foreseeable future.

[celedhring]

Dany suffered two apparently catastrophic defeats at sea. Where did she get the ships for the Dothraki and their horses?

Yeah, I wondered that as well. The whole battle scene was really contrived - as awesome as it was.

[The Minsky Moment]

Dani was too late to get the gold.  Therefore burning the food supplies is the next best thing.  Food can be imported and both protagonists have overseas connections but Cersei's is a bank.  She can use her gold/credit for arms and fighting men or for food but there is a guns and butter tradeoff.  We all know how Cersei will handle that tradeoff.   The Lannister mines are kaputt and you can only plunder the Tyrell treasury once.  If it looks like a Cersei victory will mean mass starvation that could effect hearts and minds.

[celedhring]

Dani was too late to get the gold.  Therefore burning the food supplies is the next best thing.  Food can be imported and both protagonists have overseas connections but Cersei's is a bank.  She can use her gold/credit for arms and fighting men or for food but there is a guns and butter tradeoff.  We all know how Cersei will handle that tradeoff.   The Lannister mines are kaputt and you can only plunder the Tyrell treasury once.  If it looks like a Cersei victory will mean mass starvation that could effect hearts and minds.

She'll just play the "Daenerys is starving you poor peasants" card.

[The Minsky Moment]

IMO no point in trying the reason logically about the Dorne plot.  The showrunners were faced with Martin's mess, got sucked into Dorne because they liked some of the characters, figured out they were in a time-sucking morass, and so arranged a hand-wavey bloodbath to bring it all to an immediate conclusion.  Dorne will play whatever role is convenient at the writers at this point, without regard to logical consistency which fled that vicinity long ago.

[The Minsky Moment]

Dani was too late to get the gold.  Therefore burning the food supplies is the next best thing.  Food can be imported and both protagonists have overseas connections but Cersei's is a bank.  She can use her gold/credit for arms and fighting men or for food but there is a guns and butter tradeoff.  We all know how Cersei will handle that tradeoff.   The Lannister mines are kaputt and you can only plunder the Tyrell treasury once.  If it looks like a Cersei victory will mean mass starvation that could effect hearts and minds.

She'll just play the "Daenerys is starving you poor peasants" card.

Yes but she lacks the credibility to pull it off. 

[HVC]

Is quiburn a poison enthusiast? A friend has the theory that the spear was poisoned. Seems intriguing.

[grumbler]

Like Jaimie said in Ep#3, they are in hostile territory with no supplies.  Attempting such a march would remind of a certain templar expedition against Saladin.  Doom to failure.

jamie never said that the Unsullied were in hostile territory with no supplies.  In fact, I don't recall him ever mentioning the Unsullied.

And if you think that the Reach is like the Middle-Eastern desert, you haven't been paying attention.  It is (a) allied with Danis (less some traitor houses with Randell Tarley) and (b) the most fertile land in Westeros, as has been said many  times.  And the far larger army of Dothraki didn't exactly march like the Crusaders to Hattin, in exactly that area.  So, your "doomed to failure" should read "bound to succeed."  You need to pay more attention to the show.

Dragons can't fly a thousand miles without resting and feeding, that's been pretty much established last season and besides they ain't invincible if she encounters an army alone, or he might just decide to take a nap and Dani would be left alone, and exposed, just like 2 seasons ago.

The dragons crossed the sea from Slaver's Bay to Dragonstone.  I think they can fly a few hundred miles to the Westlands.

Again, way too risky.  The ennemy controls the seas and could easily sink half the fleet before one of the dragons manages to sink a few boats.  They are strong against ships standing relatively still attacking a harbor, or disembarking troops.  If Euron attacks again at night, or in the fog, surprising them, they could sing the ship and strand Dani.

They destroy ships in moments.  Euron wouldn't even win a night battle. His ships have no defenses whatsoever against dragons, and Dani would once again control the seas.

Not knowing who's in charge of the Dornish, how long this will take, and they know Dani isn't in a position of strenght anymore, despite the dragons, this result is uncertain and still leaves the Lannister gather a lot of supplies and march their army back to KL unhurt.

None of this says that such a plan is impossible.  It surely was an option.  Not the best option, but not clearly impossible.  You claimed that your three otions were the only ones possible, and that it was easy to see that Dani could only attack Jamie's army.  I am pointing out that you lack imagination if you think that is true.

He gave a very useful advice: be as you always were, be the Queen your people have followed so far, don't be another Mad King or a Cersei, willing to sacrifice anyone for what you think is your birthright.  Like Missandei said, they don't follow her because she's related to a foreign king they never knew.  If she stands a chance of ruling peacefully, she has to prove to everyone she's different.  Otherwise, it will be burning after burning.

He said exactly what Tyriion said, advice which she had already rejected.  It was a missed opportunity to advance the plot, and wouldn't have "wrecked the show" (as you claimed) at all.

Like I said, it was pretty evident the moment we saw the convoy and the army exposed that it would be attacked.  Not exactly post hoc, I saw it as it happenned, that's all.  Not being a US president, I usually don't tweet about everything while watching tv

That's pretty much the definition of post hoc! 

again, that would be taking the viewer by the hand and spelling everything/writing it in big characters so everyone could understand without thinking. That ruins a story for me when it is done in television/cinema.

It would have disappointed you, perhaps, because of your limited imagination.  Were you pissed when Tyrion described how the Unsullied were going to take Casterly Rock?  Because that was exactly the kind of thing I am recommending the showrunners do.

For the rest of us, Jon giving sound advice that Dani took would have advanced the plot by showing Dani that Jon had good judgement, and wanted to help her cause.  A kindling romance between Danii and Jon is much more credible if she comes to respect his judgement and sheds her prejudice against him as a simple Northern barbarian.  The scene were he shows her the cave becomes more meaningful if she realizes that he is actually pretty sharp, and that his interpretations may actually have meaning. As of now, he has done precisely nothing to help her other than to back up Tyrion's advice not to attack cities with dragons (and she is fed up with Tyrion).

Well, if there's no more Lannister to feed, you need less food...

She never had more than one (small) Lannister to feed!    She mentioned the need for food for her own army.

I don't know enough of Dorne's political situation to comment.  But she might want the Greyjoy sister back, since she is a legitimate heir.

The leadership of the Iron Islands is settled by vote, not inheritance.  I am sure Dani would like to see Yara Greyjoy freed, but see no chance she would trade Jamie for her.

When Aegon conquered the kingdoms, they didn't rush to anyone defence. They sat out the war and waited for the Targaryans to attack - unsucessfully. They just waited it out until the Targaryans offered them an equal partnership: a marriage.

Stricken as non-responsive.  The Dornish situation as an independent nation at the time of Conquest is totally unrelated to their situation in the present war against the Lannisters.

As for vengeance, twice they tried, twice they failed.  Why would they again rush to it?  They're like Will. E Coyote and get stuck on a single, unatainable target instead of trying something else?  They have shown to be patient.  They waited, what, 20 years to try to take revenge for the death of their sister?  And in the books, Doran Martell has been planning his revenge since the day his sister died and he had concluded a pact to marry one of his girls to Viscerion.  And didn't he send a nephew to offer marriage to Daenerys?

The "they" that spent 20 years patiently plotting for revenge for the death of Ilya martell are dead, killed by the Sand Snakes.  The Sand Snakes supposedly had the support of the people, because they were not going to wait to take revenge, but rather get their revenge now. Haven't you been paying attention at all?

The books taught me these guys can be patient when the odds seem unsurmountable.  And again, the situation is unclear: who's ruling there?  Are they related to the Martells or where they all purged? Oberyn only had daughters and they're all dead, and none of them had kids. Whomever is left in charge maybe just doesn't care about the death of Elia Martell 20 years ago.  Althout we lack sufficient information, Dani does say she is without allies now, so it seems the Dornish can't be counted on for the foreseeable future.

More evidence that you just haven't been paying attention.  There's always an heir.  Even if they have to go back a few generations to find the heir, they will.  Check out how Henri IV of France was related to his predecessor, Henri III:  they were only connected via Louis IX, fourteen generations earlier!  it is, of course, easier in Dorne where woman can inherit.

It is true that Dani has no immediate allies, as those individuals who have directly allied with her are dead.  The heirs of those people have exactly the same basic motives to ally with her as Ellaria Sand and Olenna Tyrell, though, perhaps, without their passion (but with the new motive of wanting to avenge Ellaria and Olenna).  Dani could spend time recruiting those heirs.  She didn't, but it is unimaginative in the extreme to not even think of that as an option.

[grumbler]

Dany suffered two apparently catastrophic defeats at sea. Where did she get the ships for the Dothraki and their horses?

Yeah, I wondered that as well. The whole battle scene was really contrived - as awesome as it was.

She had enough ships to convey the Dthraki and Unsullied even before she got the Ironborn reinforcements.  She sent those ships necessary to convey the troops she wanted moved, and kept the rest to use with her remaining army.  Dunno why that would seem contrived, given that no one* knew about the new ironborn fleet.

*except presumably Varys, and he's probably a traitor.

[grumbler]

Dani was too late to get the gold.  Therefore burning the food supplies is the next best thing.  Food can be imported and both protagonists have overseas connections but Cersei's is a bank.  She can use her gold/credit for arms and fighting men or for food but there is a guns and butter tradeoff.  We all know how Cersei will handle that tradeoff.   The Lannister mines are kaputt and you can only plunder the Tyrell treasury once.  If it looks like a Cersei victory will mean mass starvation that could effect hearts and minds.

But dani could have simply captured all that food.  That would have kept it out of the hands of the Lannisters and helped her at the same time.  She doesn't have the financial resources to but food overseas that Cersei does.