A robot, boxed up, falls off a truck to float down river. A little girl without playmates -- the other kids are off to school -- finds it. Is frightened off when it moves, but then learns it can't walk.
Meanwhile, the robot factory sees it's missing and sends another one to collect it.
It involves cats, turtles, puffballs, working in a junk yard, and a downed fence. Not quite so good as the Zita books or Julia's House for Lost Creatures, but still fun.