Restaurant owner Pearl Nolan discovers the body of her friend and oyster supplier chained to the anchor of his ship. The police, led by out-of-towner Chief Inspector Mike McGuire, believe it was an accident, but Pearl, who also runs a private detective agency, suspects foul play.

When a recently retired DCI is shot dead during an English Civil War reenactment, Mike immediately suspects the victim’s wife, but she hires Pearl to find out if someone could be targeting her, too. Pearl and Mike plan a date, but a miscommunication puts them at odds.

Pearl agrees to help a woman who received a note claiming her missing husband did not die from suicide. Pearl connects the case to a grief-counseling church group and a drowning years ago. As Christmas approaches, Mike sinks into a depression, despite taking on a new flat in Whitstable.

When a mother takes her daughter out for a boat ride despite the father’s wishes, the boat starts taking on water and the two need to be rescued. Was it an accident, or were they targeted? Pearl investigates while Mike tries to enjoy his time off from police duty in the days before New Year’s Eve.

A 30-year-old skeleton washes up on the shore, and the victim has a very personal connection to Pearl; Pearl's budding romance with Mike is threatened when he identifies a suspect close to home.