The Avengers

Loki arrives on Earth, steals the Tesseract from S.H.I.E.L.D., and enslaves several minds with the scepter — including Clint Barton (Hawkeye) and Erik Selvig. In response, Fury activates the Avengers Initiative.

The team — Stark, Rogers (thawed from the ice a year earlier), Thor, Banner, Romanoff, Barton — spend most of the film failing to cooperate. Agent Phil Coulson is killed by Loki, and Fury uses his death (and some doctored trading cards) to bond them.

Loki opens a portal over Manhattan and a Chitauri army pours through. The Battle of New York is the founding public event of the superhero age. The World Security Council fires a nuclear missile at Manhattan; Stark carries it through the portal into space, sees the fleet on the other side, and nearly dies. He survives, but the vision of what's out there gives him post-traumatic anxiety and an obsession with pre-emptive defence that drives his behaviour for the next six years.

Post-credits: the first appearance of Thanos.

Standing at the end of Phase One: Six Avengers. Public superheroes. Loki in Asgardian custody. Tesseract on Asgard. Scepter (Mind Stone) confiscated by S.H.I.E.L.D. — and quietly retained by HYDRA agents inside it.