The warden of St Serf's has been found dead in the almshouse garden. He appears to have been killed during the night but there are those who are convinced he was present at that morning's service, and Gil Cunningham promptly finds himself entangled in the internal politics of the almshouse. The elderly residents, the almshouse nurse and Humphrey, her deranged favorite, have all been set against one another by the dead man's scheming — and then there is a discarded mistress and an almshouse ghost to consider as well.

Tracing the dead man's last movements between the Cathedral precinct and the shores of the Clyde, Gil is both helped and hindered by his two sisters who have come to Glasgow for his wedding to Alys. Between them they widen the field of suspicion to embrace old friends from the university, a seaman home from a distant voyage, and mad Humphrey's brother. Then an uncanny event followed by the arrival of Gil's godfather, wedding guest and patron of the almshouse, precipitates the crisis. As so often, it is clever Alys who helps Gil find the ultimate solution to this mystery.