Following on from J.J. Abrams' zippy 2009 reboot, the Starfleet Juniors return in earnest with - as the title suggests - this somewhat gloomier offering, awkwardly saddled with a morose post-9/11 sensibility. It's all just about diverting enough, and Benedict Cumberbatch's Khan is at least a more striking villain than that of the film's predecessor (though not a patch on Montalbán), but in aiming for more tenebrous hues Abrams plays against both his own strengths as a director and those of the franchise he appeared to re-energise not so long ago. (JB)