Paramount have finally released a synopsis from Star Trek II - “When the crew of the Enterprise is called back home, they find an
unstoppable force of terror from within their own organization has
detonated the fleet and everything it stands for, leaving our world in a
state of crisis. With a personal score to settle, Captain Kirk leads a
manhunt to a war-zone world to capture a one-man weapon of mass
destruction. As our heroes are propelled into an epic chess game of life
and death, love will be challenged, friendships will be torn apart, and
sacrifices must be made for the only family Kirk has left: his crew."
Many have speculated which of the franchise's villains Benedict Cumberbatch might be playing. Although some speculate the actor may portray the iconic Khan, it seems that fellow actor Karl Urban
let the secret slip. "[Cumberbatch is] awesome, he's a great addition,
and I think his Gary Mitchell is going to be exemplary," Urban told SFX
magazine while promoting "Dredd."
And although Urban later denied that Cumberbatch was playing Mitchell the official synopsis does suggest that the villain is indeed Gary Mitchell - the line from their own organization would suggest so since Gary Mitchell was a character who only appeared in the original "Star
Trek" series episode "Where No Man Has Gone Before." He and Captain Kirk
attended Starfleet Academy together, and were good friends. Later,
Mitchell became a powerful telekinetic and telepathic abilities and
thought himself a God. After increasingly villainous acts, Kirk is
forced to kill him. The coloured eyes in the teaser pic also points at Mitchell who appeared with his eyes glowing in the original Star Trek episode.