Stirling in the sweltering summer of 1967. The Summer of Love has brought Hippies and a new found freedom to the town, but Bridie O'Day's only concern is getting through her first week as a probationer at Barton Road police station. Realising her ambition of joining.CID is not going to be easy. The police force is a hierarchy of misogynous sergeants and predatory plainclothes officers. Promotion for women is unheard of. When Bridie and her idle, bubblegum blowing partner, Harry Bluett are called out to a disturbance at the Raploch, Stirlings most notorious housing scheme, she stumbles upon the body of herbalist Helen Swankie. It's clear Helen has been murdered and if she could just solve the crime before the molodorous and obnoxious Detective Sergeant Gus Wylie, it can only help her chances of getting a quick move to CID, can't it? With the help of genealogist Charlie Fleck and her foulmouthed parrot 'The Bosun', Bridie begins her own investigation, but when a second body turns up it seems the motive for the killings is far from clear. Bridie and Charlie embark on a trip deep into the past to unearth a secret buried in medieval times. The murders themselves are linked to one of the darkest tragedies of the previous decade. Will the pair be able to bring the perpetrator to justice before the murderers twisted logic causes yet another death?