Book 12 in the Euphemia Martins Mysteries series

In the run up to Christmas 1913, Euphemia's stepfather, the Bishop, proposes a family lunch at his club. Bertram, who is staying with the Mullers, runs her up to town in his car. He decides to let Euphemia confront her family alone before introducing himself as her fiancé. He retreats to the Billiard Room only to be summoned when a murder occurs.
The members are very reluctant to call the police and Bertram is asked to sort out what actually happened before the police arrive. He enlists Euphemia's help, to her mother's shock and, to everyone's surprise, the Bishop's approval.