Once a month, the seven members of the Black Widowers Club gather for dinner at their favourite restaurant. To each dinner a guest is invited, and each guest has a problem too large and complex to solve on his own. This is the fifth collection of the "Black Widowers" stories.

Each month the Black Widowers, an urbane club of cerebral adventurers, meet at the Milano Restaurant for dinner. And each month a single guest is invited and subjected to a genial but intense grilling on the meaning of his existence. Inevitably the guest confides some puzzling question or strange occurrence in his life - the inexplicable disappearance of a good luck charm, for instance, or how a four-leaf clover can identify a traitor - tantalizing conundrums that the great Holmes himself would have enjoyed solving.

When the Black Widowers are stumped (as invariably happens), they turn to their faithful waiter Henry, who serves up perfectly grilled salmon and devilishly clever answers with equal aplomb.