The Doctor Who Christmas episode is as much a holiday tradition in some households as mistletoe or feats of strength. This year's installment -- The Return of Doctor Mysterio -- sees the Doctor (Peter Capaldi) in New York as a swarm of brain-swapping aliens prepare to attack the city, or at least Manhattan. Aided by his assistant Nardole (Little Britain's Matt Lucas), the Doctor attempts to forestall disaster with the help of a reporter and a masked man who insists on being called The Ghost. The Return of Doctor Mysterio combines super heroics and super science for an usual kind of Christmas special unusual even for Doctor Who. You can see it locally at 7 p.m. tonight at Wehrenberg Ronnies 20 Cine (5320 South Lindbergh Boulevard; www.fathomevents). Tickets are $12.50 to $15.