Sam has been hired by Miss Elizabeth Collie to investigate a number of thefts that have occurred at the Miss Wigginson School for Girls. Herself and Ursula Cavanagh, one of the board directors, have decided that they know who the culprit is, they just have to prove it. They have no evidence but they just want Sam to prove that their suspicions are correct. Glorie Thomas is Miss Elizabeth Collie's assistant, and also the one under surveillance by Sam. She has done nothing to make anyone think that she is the thief, and has had none of the stolen items recovered from her possession. There is no evidence at all to support Miss Ursula and Miss Elizabeth's claim, so why are they so insistent?