New Delhi, July 20 -- The first trailer for Avengers: Doomsday has brought together several generations of Marvel superheroes, with Doctor Doom emerging as the force threatening to tear the multiverse apart.

The trailer opens with a background narration by Doctor Doom, played by Robert Downey Jr, before introducing the various teams preparing to face the threat. The Fantastic Four, the X-Men and the new Avengers are all shown alongside returning members of the older Avengers, including Thor. Loki also appears in the footage.

The trailer establishes the scale of the conflict as Marvel's heroes assemble to confront Doom and the multiverse-crossing war he is preparing to unleash. Thor is shown facing off against Doom before reuniting with ...