Whilst on holiday in Switzerland, the Saint's approached by a young woman, who says she'd been raised in Sweden by her mother, at the behest of her father, a Russian professor. He's just arrived in Geneva, to attend a conference, and is anxious to defect. The professor's being held prisoner in a chateau by security, and Irma begs Simon to free him. A plot's hatched, but inevitably, not all is what it seems to be.