So what happens after the midpoint? Well this is where I throw everything and the kitchen sink at the protagonist. The fun stuff is at an end and now I get down to the meat of the screenplay. This is where I make the hero suffer.
In this section things should get gradually worse for the protagonist. Really bad in fact. Bloody awful and desperate for him, if the truth be told. I pile the shit on and watch him suffer. What doesn't kill him, makes him stronger. It should be so bad for the protagonist the audience should be wondering how the hell he is going to get out of this a) alive and b) triumphant.
The hero should be at his lowest point just before the break into act three. He should be broken. He should be defeated. He should be at the point where he cannot see any way, logical or illogical, to get through the problems facing him. This is where the antagonist rises to the height of his power, on the verge of triumph.
In a thriller this is the section the hero begins to take the fight back to the antagonist, instead of just reacting to what happens to him. Now he must be proactive. Now he must make the antagonist react. He will still fail at what he attempts, maybe even have the odd small victory here now and again, but fail he must if he is to be the broken person he needs to be by the end of the act.
As I said above, just before the break into act three, when the hero is at his lowest point, everything has gone wrong, the antagonist has the upper hand and the hero stares defeat in the face. Here he must learn a truth, something about himself, or others, or a situation, so he has the tools, mental or otherwise, to finish the job in act three. Call it a revelation if you want, but it must allow the character to grow into the person he 'needs' to be.
As I write strong character driven screenplays, for me the hero always has to learn something important about himself. He has to realise it was a fault within himself, a personal flaw, that has prevented him from succeeding. Only when he realises this can he move on, grow and step into act three.
The final part - ACT 3 - next week.