It's hard to imagine how the world could not be safe with the likes of superheroes protecting it.
But such is the life they lead that this group of saviours must dig deep to prevail. The Avengers are summoned by the director of an international peace-keeping agency called S.H.I.E.L.D -led by agent Nick Fury (Samuel L. Jackson) - with the Earth in imminent danger.
Loki, an extraterrestrial visitor, has come to Earth to claim and activate The Tesseract, an energy source of unknown potential.When this is done, a portal will open allowing the Earth to be invaded by creatures with only death and invasion in mind.
Loki is an illusive and powerful adversary who knows the Avengers will be useless if he can divide them.
With such incredible personalities like Iron Man (Robert Downey Jr), Captain America (Steve Rogers), the Incredible Hulk (Mark Ruffalo), Thor (Chris Evans), Black Widow (Scarlett Johansson) and Hawkeye (Jeremy Renner) in play, creating a team which will work together is Fury's biggest problem.
The two things that stand out in The Avengers and put it a cut above its cinematic predecessors are the action and the humour.
At times, when the chips are down and all is almost lost, humour regularly pops out in a clever and most welcome way.
And the action is top rate as the city of Manhattan suffers a serious pounding under enemy attack - not to mention the damage done when the Incredible Hulk loses his infamous temper.