When utilized as a movie plot device, time travel has the ability to do a great many things. It can refresh an ailing franchise, introduce new characters, and even establish an alternate timeline that introduces the possibilities of new scenarios without adversely affecting the previously established mythology. As J.J. Abrams’ Star Trek showed, all of this can also be accomplished without a movie feeling like a massive, unnecessarily complicated game of connect-the-dots.

Bryan Singer’s X-Men: Days of Future Past is a time-travel tale that serves as both sequel and mash-up, combining the casts from the original X-Men trilogy with the youngsters from the swinging, 1960s-set X-Men: First Class. The result, sadly, is less than the sum of its parts. Instead of a thrilling new adventure, it plays like a hugely expensive remake of It’s a Wonderful Life, with Hugh Jackman’s Wolverine acting as an adamantium-clawed guardian angel forced to show the bickering mutants how bad the world will be if they don't just get along.