A blind recluse with an unusual hobby, a telekinetic pantomime dwarf, an embittered hook-handed clown, a serial killer-obsessed man-child and a deranged but caring midwife all receive the ominous message 'I know what you did'. The past catches up with these five seemingly unconnected characters as they go about their darkly comic present-day lives.

Mr Lomax enlists the help of his care worker in the quest to complete his unusual collection. Things go from bad to worse when a misunderstanding leads David and his mum to cover up for his incompetence at the murder mystery evening. Robert is surprised when Debbie asks him out on a dinner date and midwife Joy enlightens the morning group with the perils of choosing a water birth.

This episode reveals the story of how Mr Jelly, the one-handed children's entertainer, ended up the way he is. Mr Lomax travels to the private auction of Snappy the Crocodile in Dudley. David and his mum dispatch their next victim disguised as beauticians, and Robert wreaks his revenge on Debbie during a midweek matinee of Snow White.

David and his mum are mid-murder when an unexpected visitor throws them into panic. Who is the mystery caller? What will happen to the body in the trunk? And will Maureen finally get to try one of those pyramid teabags?

Midwife Joy is left alone with her demonstration doll Freddy when a Pinocchio-like miracle happens. David and his mum lure their next victim to a waxwork museum, and Mr Jolly explains to Mr Jelly the reason for the blackmail letters.

Robert uses Debbie's amnesia for his own ends. A battle of wills ensues with more than cross words flying through the air. Mr Jelly is entertaining an old people's home when a phone call from Mr Jolly plunges him back into danger. Maureen learns the truth about her killing spree. Mr Lomax has acquired a new home help.

All of the characters are drawn back to the scene of their crime. Who has summoned them there and for what terrible purpose? Meanwhile, Kerry takes Robert from the theatre to the heart of the deep, dark woods. Will anyone survive the great day of judgement?

Phil, a researcher for the TV series Dale Winton's Overnight Ghost Hunt, goes to Ravenhill Hospital to expect it for a forthcoming shoot. While there he is haunted by visions which manifest themselves into the form of four stories. The special guest stars Imelda Staunton, Katherine Parkinson, Sarah Solemani, Jason Watkins, Mark Bonnar and David Cann.

The survivors of the explosion at Ravenhill Psychiatric Hospital reunite to bury one of their number killed in the blast, but there is to be no rest for the wicked.

The search for the missing locket continues with the investigation turning to Christopher Biggins for answers. Meanwhile, we find out what happened to Robert and Kerry as we return to the mysterious cottage in the woods.

Mr Lomax reveals more about his past and his hatred for Tony Hancock becomes clear. Meanwhile Mr Jelly arrives at a booking meant to be for Mr Jolly and hopes no one will tell the difference.

Desperate measures are called for as Jeremy Goode searches for the missing library book. Mrs Wren is in peril from several parties and only one man can save her. But will he be bothered?

With danger mounting and few witnesses left, Tealeaf, with the help of Peter Bishop, tries to solve the mystery of the locket. Things don't quite go to plan. Elsewhere, once again Jelly becomes Jolly with unexpected results.

The secret of the missing locket is finally exposed and the enormity of what is at stake revealed. But are there enough characters left alive to care?