Having been plagued by false memories of an alien amusement park, the Doctor and the gang went on the hunt to discover the truth. On a curiously colorful planet, a perturbed alien named Friffle reveals his people are being taken by the mysterious Mr Henderson - a man who bears a striking resemblance to Santa Claus! Taken as prisoners in his grotto-like lair, the Doctor resolves to find out exactly what he's plotting...