The Case of the Oily Rainbow / The Case of the Disappearing Friends Fishtronaut and Rosybarb notice a rainbow-colored oil slick on the lake surface, that spreads fast! They know it can make the water very polluted. The POP offers a few clues and off they go! // Fishtronaut, in the water, and Zeek on land, play with new friends: tadpoles and furry caterpillars. Once play time is over, the creatures suddenly disappear! What’s going on at Smiling Trees Park?