This isn’t the third installment in the so-called “Blood and Ice Cream Trilogy” featuring Simon Pegg and Nick Frost. Note the missing element: Edgar Wright, who directed and co-wrote with Pegg both Shaun of the Dead and Hot Fuzz, in which Pegg and Frost re-enacted at least one scene from every buddy-cop movie ever made. Greg Mottola instead directs Paul, and he’s an escapee from Judd Apatow’s stable—along with Seth Rogen, who voices the title character, a shirtless, foul-mouthed, dope-smoking, ass-flashing E.T. It’s the ultimate modern-comedy crossover, as damp a dork’s dream as when Kirk met Picard in Star Trek: Generations, among the approximately 382 films referenced. Wright’s absence is notable; he could have helped Frost and Pegg—playing, respectively, a stalled sci-fi novelist and his illustrator/best friend who chaperone Paul in an RV—stuff Mel Brooks back into their Han Solo Underoos. Worse, the film plods in places, and Wright never wastes a moment. Paul, though, is a simple pleasure—half its dialogue consists of lines lifted from every sci-fi comfort-food staple fed to growing fanboys in the ’70s and ’80s. Kristin Wiig, as a cycloptic Creationist, is the highlight, bringing depth and genuine warmth to the thankless, one-dimensional role of a God-fearing Bible-thumper. An alien concept indeed.