SUPERHERO ensemble The Avengers blast and smash their way back to cinemas today, Thursday.

Age of Ultron is the sequel to the 2012 film featuring Iron Man, Captain America, Thor and The Incredible Hulk.

And with the popularity of Marvel Comics characters on the big screen showing no signs of waning, the movie's opening weekend is poised to pulverise box office records.

The plot sees Tony Stark (Robert Downey Jr) repurpose an alien artificial intelligence as a peacekeeping program called Ultron (James Spader).

But there is a slight snag to the plan when self-aware Ultron decides that humans are the main enemy and sets out to eradicate them from Earth.

The film fleshes out the back stories of Stan Lee's iconic characters while introducing a number of new faces along the way.

This includes Aaron Taylor-Johnson as comic book favourite Quicksilver, Elizabeth Olsen as Scarlet Witch and Paul Bettany as android Vision.

As with all Marvel films, expect spectacular battles and plenty of polished quips.

Age of Ultron is also set to lay the groundwork for the 2016 blockbuster, Captain America: Civil War, which will tear The Avengers apart as governments worldwide prepare to pass an act regulating super-humans.

Joss Whedon, who was behind Firefly, Buffy The Vampire Slayer and Angel, returns to the director's chair after helming The Avengers.

He has managed to cram in almost all of the popular supporting characters like Samuel L. Jackson as Nick Fury, Scarlett Johansson as Black Widow and Jeremy Renner as Hawkeye.

And after a deal was struck between Marvel Studios and Sony Pictures to reintroduce Spider-Man into the Marvel cinematic universe, rumour has it that a certain web-slinger might appear after the end credits...