Animated stories of Clifford the Big Red Dog before he got so big. Emily has lost one of her lucky socks and Clifford is determined to hunt it down for her. After a thorough search of her room and an investigation of Flo and Zo's secret kitten stash, he's no closer to victory. On a hunch, he accompanies Mr. Howard to the laundry room where he finds the Sidarskys have turned the sock into a bed for their youngest mouse.