This tongue-in-cheek retro indulgence from writer Simon Barrett and director Adam Wingard, most famously the makers of You’re Next, harkens back to a time when movie thrillers being sort of stupid didn’t automatically disqualify them from being also sort of entertaining. So now we know what Dan Stevens got himself killed off of Downton Abbey to do. In The Guest, Stevens plays a drifter who insinuates himself into a grieving small-town family, claiming to be the war buddy of their son who died in action, and offering his charming-slash-psycho services as general handyman and gratuitously deadly protector. Evidently enjoying himself, Stevens overdoes everything just slightly and with great precision. He’s a monster of lethal smarm, like some strange Terminator sent back from an empty future to destroy us all with its Bradley Cooper impression. Barrett and Wingard’s homage to the junk heap of glibly amoral ’80s action schlock seems sarcastic but not unaffectionate. Lusciously lit, attentively shot, and insistently scored with the brooding throb of synth pop, it’s all very intense, but funny about its intensity, too. The Guest hails from the same school of knowing nostalgia as the recent indie throwback Ping Pong Summer, but it’s craftier — and crazier, as becomes very clear in a literal and figurative fun-house climax.