The Marvel Comics superhero Captain America was born of World War II, so if you're going to do the origin story in a movie you'd better set it in the 1940s. But how, then, to reconcile that hero with the 21st-century mega-blockbuster The Avengers, a 2012 summit meeting of the Marvel giants, where Captain America joins Iron Man and the Incredible Hulk and other super pals? Stick around, and we'll get to that. In 1943, a sawed-off (but gung-ho) military reject named Steve Rogers is enlisted in a super-secret experiment masterminded by adorable scientist Stanley Tucci and skeptical military bigwig Tommy Lee Jones. Rogers emerges, taller and sporting greatly expanded pectoral muscles, along with a keen ability to bounce back from injury. In both sections Rogers is played by Chris Evans, whose sly humor makes him a good choice for the otherwise stalwart Cap. (Benjamin Button-esque effects create the shrinky Rogers, with Evans's head attached.) The film comes up with a viable explanation for the red-white-and-blue suit 'n' shield--Rogers is initially trotted out as a war bonds fundraiser, in costume--and a rousing first combat mission for our hero, who finally gets fed up with being a poster boy. Director Joe Johnston (The Wolfman) makes a lot of pretty pictures along the way, although the war action goes generic for a while and the climax feels a little rushed. Kudos to Hugo Weaving, who makes his Nazi villain a grand adversary (with, if the ear doesn't lie, an imitation of Werner Herzog's accent). If most of the movie is enjoyable, the final 15 minutes or so reveals a curious weakness in the overall design: because Captain America needs to pop up in The Avengers, the resolution of the 1943 story line must include a bridge to the 21st century, which makes for some tortured (and unsatisfying) plot developments. Nevertheless: that shield is really cool. --Robert Horton