Professor Bufo trains Oso to find the real Agent Wolfie in a group of Wolfie robots. Oso tries figuring out who is the real Wolfie when he gets a special alert. Three brothers--Juan, Jesus, and Julio--are shopping with their mom at a department store in Madrid. Juan stops to look at a toy train, and he gets separated from his mom and brothers. Now he is lost and scared. Will Oso help Juan find his family?