The team of misfit superheroes is back! Avengers: Age of Ultron will hit Hong Kong's cinemas on Thursday, and a lot has happened in the Marvel universe since they were last on the big screen. If you haven't seen or can't remember all of the previous movies, here's a quick guide to what has happened since the first Avengers movie. Obviously, there'll be spoilers ahead.
After the first Avengers movie, billionaire Tony Stark struggled with his traumatic memories of the epic battle in New York, where he guided a nuclear missile into space and fell back down to Earth.
His troubles weren't over though. In Iron Man 3, a rival scientist destroyed Stark's Malibu home. Although he and his girlfriend (and Stark Industries CEO) Pepper Potts triumphed in the end, Stark blew up all of his Iron Man suits to prove his devotion to Pepper. And yet, clearly he returns as Iron Man in Age of Ultron, with new and bigger suits. So much for Pepper.
The Asgardian god of thunder joined the Avengers after his brother Loki, god of mischief, caused havoc on earth during the first Avengers movie.
Since then, Thor has run into Loki again in Thor: The Dark World, where they worked together to defeat an evil elf. However, Loki faked his own death and is now masquerading as Thor's father Odin on the Asgardian throne.
In Thor: The Dark World, a lot of the movie revolves around the heroes and villain trying to get the Aether, a seemingly all-powerful red substance, which has been confirmed to be an Infinity Stone. There's a lot to explain, but basically these stones are magical artefacts that all fit on an Infinity Gauntlet, which has been brilliantly described online as a "gold oven mitt" with five gem holes in it. The gauntlet grants infinite power, and it'll be the focus of the next Avengers movies - Infinity War Parts 1 and 2. At the end of Thor: The Dark World, the Aether is in the hands of a mysterious character called The Collector.
A lot happens in Captain America: The Winter Soldier, but for the purposes of understanding Age of Ultron, all you really need to know is that by the end, it turns out that Hydra, the evil terrorist organisation, is alive and well. They have Loki's mind-controlling sceptre from the first Avengers movie, as well as two people in cages: a young man who is moving so fast he becomes a blur, and a young woman levitating small blocks in the air. That'll be Quicksilver, who has super speed, and Scarlet Witch, who is telekinetic and can get inside people's heads.
You may remember Quicksilver from a fantastic slow motion / super speed scene in last year's X-Men: Days of Future Past. That's different, because it's a movie from Fox, which owns the rights to the X-Men. Yes, that means there'll be two versions of Quicksilver, thanks to the complicated situation regarding which movie studios own which Marvel characters.
The rest of the team
Just in case you've forgotten them, here are the remaining members of the Avengers (and the team's only two members without superpowers): master spy Natasha Romanoff, also known as Black Widow; and expert archer and marksman Clint Barton, also known as Hawkeye. Of course, there's also scientist Bruce Banner, who can turn into a giant raging green monster known as the Hulk, ever since he was exposed to too much gamma radiation. And let's not forget the man who banded all these misfits together: Nick Fury.
Age of Ultron won't be the last you see of the Avengers. They will be back in Infinity War: Part 1, which is scheduled for 2018.
Avengers: Age of Ultron opens on Thursday