Merciless Marvin the Magnificent is back! (Which means, of course, that Fats the Fuse and Raymond the Rat are along for the ride.) When Marvin makes his way into Macy's department store, he thinks he has discovered the best deal a mouse could wish for. But no sooner has he gathered his gang and then gotten them cozily settled into a dollhouse in the toy department than Macy's Santa goes missing. The world outside is cold and dangerous. But Marvin and his pals will risk whatever they must to crack the crime, rescue Santa, and save Christmas!