With Scott Corbett at the typewriter and Paul Galdone at the drawing board, mischievous scalawags like Kerby and Fenton can prepare for another violent attack of giggles. Left alone in their clubhouse for the night, the boys suddenly notice the absence of Waldo, Kerby's dog. They remember eccentric Mrs. Graymalkin's advice to rely on one's chemistry set in a time of crisis and so, after mixing a potent concoction, the boys are astounded to see the liquid transformed into a mass of pictures. With their soluble television screen, Kerby and Fenton set out to locate Waldo whom they can see in the beaker. The destruction of the beaker forces the boys to use their own heads. They manage to retrieve Waldo from the delicatessen- in a wedding cake box, return home via Mrs. Graymalkin's black limousine in time to answer father's phone call and report that all is well. They also manage to bring to a grand finale a riotous escapade into the secret world of real -- boy; adventure. How to explain the magic beaker and Mrs. Graymalkin's broomstick tendencies? Easy -- depend on science. It's bound to come up with the answers some day. Besides, who can really explain television? The fantasy here is so credible, the realism so earthbound that few young readers will question the mixture. First rate entertainment.