Young Tom French is found dead, lying in a marsh on the Norfolk coast, with his head bashed in and his binoculars still around his neck. One of the best birders in England, Tom had put the village of Rushy on the birdwatching map. Everyone liked him. Or did they?

George Palmer-Jones, an elderly birdwatcher who decides quietly to look into the brutal crime, discovers mixed feelings aplenty. Still, he remains baffled by a deed that could have been motivated by thwarted love, pure envy, or something else altogether.

But as he and his fellow ‘twitchers’ flock from Norfolk to Scotland to the Scilly Isles in response to rumours of rare sightings, George – with help from his lovely wife, Molly – gradually discerns the true markings of a killer. All he has to do is prove it ... before the murderer strikes again.