Attending a farewell presentation for ex-criminal Ronnie Tyler in Midsomer Holm. a safe haven for reformed offender, Barnaby encounters ex-colleague Jack Colby, Jack and his wife Professor Gina Colby live with Lord Holm at Holm Manor. Gina is fated for her work reforming criminals and Jack is now the administrator of the halfway house. The following morning Jack's body is found bludgeoned to death. With Jones's help, Barnaby has to go back 16 years to solve this mystery.