The entire first sequence of Bryan Singer's "X-Men: Days of Future Past" was unveiled at yesterday's CinemaCon event in Las Vegas. The footage treated attendees to a glimpse at the upcoming film and the deaths of many "X-Men" characters, Cinemablend has learned.

Be warned, the following description of the scene contains spoilers.

The scene opens in an apocalyptic future where Sentinels hunt down the last remaining mutants. As IGN pointed out, these mutant-hunting robots in the new film appear totally different as compared to those in the comics. They feature a malleable physical appearance, which is similar to the T-1000 model in "Terminator 2". The Sentinels also posses the ability to adapt to or absorb the mutants' powers, making them seemingly indestructible.

The footage then shows an underground stronghold manned by Colossus, Warpath, Blink, Kitty Pryde, Bishop, and Sunspot. As the Sentinels blast their way through the walls, the small band of mutants form a circular defensive pattern.

Sunspot uses his powers to temporarily stun one of the Sentinels and Warpath cuts through another robot with the help of his blades. Blink then opens up a wormhole to reveal a waiting and battle-ready Ice Man.

At this point, it would seem as though the group has everything under control. But then, the Sentinels start to display their anti-mutant abilities.

The one battling the mighty Colossus turns into the same metallic material as him, the Sentinel that Sunspot stunned cooled itself to counter his heat blasts, while the other one increased its temperature to avoid being frozen by Ice Man.

Almost immediately, the Sentinels begin to dispatch the helpless mutants one by one. Ice Man gets decapitated, Blink is stabbed through the chest, Warpath is killed off-screen by a face blast, and Colossus gets destroyed.

While their comrades were facing off against the Sentinels, Kitty and Bishop went in a different room where she uses what seemed to be her new telepathic powers on him. As the Sentinels close in on them, everything in the room, including the two remaining mutants, the robots, and other objects, disappear.

The scene suggests that Bishop and Kitty were able to travel back in time to change the past, presumably saving their mutant friends from a grim future.