© ITV/Mark Bourdillon

Members of the Midsomer-in-the-Marsh Ornithological Society (MMOS) fall out when Ralph Ford claims he's spotted a blue-crested hoopoe. The sighting means he's the winner of this year's list competition, but other members including president Patrick Morgan say the bird would never be seen in Midsomer as it's not native to these shores.


Ralph storms out of their meeting and the next day, Patrick is found dead in Swansdown Lake - scene of the alleged bird sighting. His body is entangled in a mist net used to catch birds for ringing and he has a head injury. The dead man's wife Nina, a former Russian prima ballerina, is shocked at the news, especially as she's just discovered she's pregnant. But, unbeknown to the detectives, Patrick had accused her of sleeping with another man.


Patrick was lured to his death by a bird alert sent from Ralph Ford's phone. Ford, a professional taxidermist, claims his phone was stolen. Birdwatcher Tim Whitley unwittingly captured the sound of Patrick's attack on tape, on the stroke of midnight.


Olivia Carter, secretary of the MMOS, seems traumatised by Patrick's death, while belligerent farmer George Napier is glad to be rid of the former city financier with his grand ideas about saving the wetlands when Napier wants to drain and farm them.


Dr Kate Wilding reveals that Patrick had a vasectomy - Nina's child cannot be his. Nina says she had a drunken fling at a party in London, but Jones is sure her lover is a local man. Could he be a member of the MMOS or even Dave Foxely, a petty criminal?


GP Ian Markham claims his relationship with Nina was purely professional, while fellow twitcher and former orchestral performer Michael Hipman says he was playing his oboe at midnight. Later Nina visits the surgery in tears and is comforted by the doctor. Pictures of them together are delivered anonymously to Barnaby.


Ralph meets Foxely in the woods and demands money. At midnight, Dr Markham is also in the woods - where he is shot dead. Nina finally admits the GP was her lover.


A meeting of the remaining members of the MMOS falls into disarray. Cartridges from Foxely's gun match ones found by Dr Markham's body but Foxely says they're from shooting vermin. However, he reveals Ralph did find the rare hoopoe but only after Foxely shot it down in error. The detectives go to Ralph's workshop and find the hoopoe - stuffed. But Ralph is vegetarian and says he couldn't hurt another living creature.


As Nina leads her ballet pupils through their end of year concert, Sarah shows Barnaby footage of the ballerina in her prime. In the theatre, Barnaby spots a familiar face and realises the extent of the murderer's obsession. Can he stop Nina from meeting a similar fate as the swan in the famous ballet?