Steven's Twin

Elizabeth and Jessica Wakefield get free sundaes from Casey's Ice Cream Parlor--just for being twins. Their bother, Steven, is jealous. He wants a free sundae, too. So Steven makes up his own twin and fools everyone at Casey's. Now he has to fool his parents and the newspaper reporter who comes to interview the unusual family with two sets of twins. How long can Steven be two people at the same time?