When a neighbor hires Nancy, Bess, and George to take care of her eighteen-month-old identical twins, the girls are happy to help. After all, the Clue Crew has stopped would-be thieves, uncovered scams, and recovered stolen objects -- how hard can watching a couple of babies be?

But being a mother's helper is trickier than they thought, especially when the twins' toys start disappearing. Can the Clue Crew look after the babies and figure out who's taking the toys, or are they in too far over their heads this time?