It is the day before their wedding and Trish is freaking out about the finishing touches, so Henry tells her to take the morning off and spend time with her father, Thomas, as the American murder-mystery drama continues.

However, the bonding bike ride Trish and he embark on through the woods takes a dangerous turn when they trip a booby trap and a strange man sets his dog on them.

Meanwhile, Abby, who spent the night on Jimmy’s sofa, is surprised he and her sheriff father have breakfast plans. Her dad invites her to the family house later to pick up some mementos but he is not home when she arrives. After nosing around in the attic she discovers her father’s obsession: the Wakefield murders. Not just the original slayings, but annotated photos and cuttings about other, more recent murders that may be connected. Could they be copycat killings?

At the church, Sheriff Mills is helping Henry who, while looking for missing Reverend Fain, found a rotting animal carcass left on the altar. On the floor he spots a firecracker like the ones his brother, JD, and Madison had used earlier at the Inn. Henry confronts JD angrily and is promised one more surprise…

That afternoon the wedding rehearsal goes ahead, despite the absences of Fain, Booth, Lucy, Chloe and Cal. At the altar, Henry is standing with Trish and Thomas when the use of the light switch triggers a deadly device…

Sunday 20 September
9.00-9.40pm BBC THREE