Die Hard

25: For the first time the antagonist, Hans Gruber speaks to the hostages. He gives details of an exec he will later execute. The birth of something new.

45: McClane tries to get the police dispatcher to believe in him. We cut to a store where we first meet Al Powell, the cop who later befriends McClane. Sgt. Powell buys candy and learns about possible trouble at the building. Now that I'm aware.

60: McClane and Gruber talk for the first time. Gruber wants to know who McClane is. McClane lets Gruber know he's not someone to take lightly and forces Gruber to take action to find him. There's no going back now.

-45: McClane and Sgt. Powell talk about kids and family. Gruber learns from a reporter that McClane is a cop and his wife is a hostage, now Gruber has leverage over McClane. Discovery.

-25: The FBI forces the shutting down of an electrical grid that opens the bank vault for the antagonists. Just before this scene, Sgt. Powell warns McClane the Feds are in charge. McClane takes matters into his own hands and resolves the conflict on his own with some help from Sgt. Powell at the end. The final turning point.