[3] In a review in The Observer Maurice Richardson felt it "tails off a bit after a flying start, but you'll read away" while later in the Times Literary Supplement he concluded "Towards the end the shifting of the scene from the Norfolk Broads, where one victim is drowned, to Hampshire, where another is beaten to death with a cricket bat, becomes bewilderingly abrupt.

While visiting an old school friend in Norfolk Mrs Bradley goes boating on a nearby river, where she catches sight of a young man pushing a woman into the water although she manages to survive.

It coincides with an invitation to young Irish-born teacher Thomas Donagh to tutor Caux's other grandson Derry at his Hampshire manor house.

Intrigued by the two cases Mrs Bradley begins to develop a theory that the two twins, separated from each other a decade before aged seven when their parents were killed in an accident, have been routinely switching places between Hampshire and Norfolk.

With the assistance of Scotland Yard she sets out to gather the remaining strands of evidence together, and this requires Donagh to invite Sir Adrian Caux to take part in a second cricket match.