Why is there a baby on the Petterils' doorstep?

The discovery turns the household upside down. Where did the infant come from? Who and where is its mother, and is there a connection to someone in Petteril House? Inevitably, everyone has a scandalous theory, but tracing the truth of the baby's journey is much harder.

The Petterils find themselves having to defend each other's honour, while investigating their servants, neighbours, family, and friends, all of whom seem to have secrets worth hiding. Worse, the tiny human who is the cause of all the upheaval, dribbles and squirms its way under their skins and into their hearts...