It's 1965, and outside of a posh estate, a sinister man conducts surveillance, while within, black-tied gentlemen make high-stakes wagers. But as dawn breaks, it stirs a dissipated scene of older men and teenage girls, awakening entangled. And the next day, fifteen-year-old Oxford schoolgirl Mary Tremlett is reported missing, presumed dead. Last seen waiting at a bus stop in the rain in the early hours of Sunday morning, she left behind few clues and many secrets.

Endeavour Morse, a rookie Detective Constable who only the day before was writing his letter of resignation from the force, now finds himself en route to Oxford to assist in the search for Mary. He returns not as a student but as a rookie cop, to the very university he'd abruptly left just a few years earlier. And the welcome he receives from his contemptuous DS, Arthur Lott, emphasizes his position of utter subordination.

But Endeavour, a loner who listens to opera as his generation is swept up in rock 'n' roll and revolution, cannot help but apply his cerebral instincts to the case. Where others see the clichéd teenage girl's romance with poetry in the stack of books by Mary's bed, Endeavour sees valuable first editions; in her barely-started crossword puzzles he sees a cryptic code; and in Detective Inspector Fred Thursday, he sees the possibly of an ally. Deciphering the code provides a vital break, leading them to Mary's corpse, but the case deepens when a seemingly unconnected death sidetracks Endeavour and reveals unsavory dealings in the heart of the ivory tower.

The retired soprano Rosalind Stromming, wife of an Oxford don with a murky connection to the case, provides refuge to the troubled young man striving to find his place and banish his demons. But only finding the identity of the crossword writer known as "Oz," and extracting the truth from a group of far too worldly teenage girls, will ensure him a chance at catching Mary's killer.

Read full synopsis
Warning: Contains significant plot spoilers

Hide full synopsis
Warning: Contains significant plot spoilers

Daybreak stirs the dissipated morning-after scene of a party in a posh estate, where young girls are entwined with older men. Out in the rain, a driver spots a young woman in a Mondrian print dress waiting at a bus stop before dashing into the woods. It is 6am.

In another city, Endeavour Morse, a rookie Detective Constable, writes a letter of resignation from the force. But within hours he's on his way to Oxford with other officers drafted to help search for Mary Tremlett, a missing 15-year-old. DS Arthur Lott shows blatant contempt for "college boy" Endeavour.

Mary's distraught father and older sister, Sharon, reveal little. But tucked into Mary's valuable first editions of poetry, presumably beyond a schoolgirl's expenses, he finds crossword puzzles with only the first clue across and the last clue down filled in. It's a code: the down clue invariably contains a number and the across clue is always a location near Oxford. But Endeavour is sidetracked, asked to investigate the suicide of Oxford student Miles Percival. Percival's tutor, Dr. Rowan Stromming, describes his student as having fallen apart several months before, showing up late and drunk to class. Endeavour is drawn to Stromming's beautiful wife, Rosalind, a former opera diva who gave up her career for marriage.

Mary's corpse is found at the location indicated by the most recent puzzle, confirming Endeavour's decoding. Crushed beside her body is Miles Percival's watch, stopped at 8:00. But Endeavour's search for the crossword's author, known only as "Oz," yields nothing. From a local car mechanic, he learns that Mary was Percival's girlfriend. Percival's roommate indicates that the couple had broken up six months before. The jilted boy thought she was seeing someone else: Dr. Stromming!

Endeavour learns that Stromming, seeing the voluptuous girl on Percival's arm at a college event, had placed a bet with a colleague as to whether they could pass her off as a student. Stromming tutored Mary, nothing more. But Endeavour realizes that Stromming is Oz. Confronted, Stromming admits to authoring the puzzles, creating assignations, and an illicit relationship. But he denies murder. In fact, Mary hadn't shown up at that week's location. He works several weeks ahead with his puzzles and concludes that he must have given the wrong one to Rosalind for submission by mistake. Rosalind explains that she had asked a student she knows from the choir, who'd stopped by to talk with her husband, to mail the puzzle for her: Miles Percival.

But the 6am Sunday sighting of Mary puts Stromming in the clear — 8:00 must have been am, not pm, and Rosalind confirms that they were at church together at that time. Now, the watch, the puzzle, and the suicide indict Percival, and Endeavour is devastated that his instincts were so wrong. Placing a letter of resignation on Chief Superintendent Crisp's desk, he sees a picture of Crisp's daughter; she is one of Mary's friends in the close group of girls. He questions her and learns of far more sordid dealings — the schoolgirls were recruited to debauched parties with powerful rich men. Garage owner Teddy Samuels procured the girls, but threatens DI Thursday, saying that many of the most powerful men of Oxford and beyond are involved. DS Lott was in on it, and Crisp himself was being blackmailed, his silence bought by incriminating pictures taken of his daughter.

But for Endeavour, everything comes back to the dress found next to Mary's naked corpse, several sizes too small for the voluptuous girl. Only by tracking down the dress's purchase is he able to piece together the whole mystery: It was Rosalind, fully aware of her husband's affair, who bought two identical dresses (albeit in her own size); who framed Percival by giving him the wrong crossword puzzle and stealing his watch; who lured Mary to the meeting place and killed her there, smashed the watch at 8:00 to solidify her husband's alibi, then, dressed in the Mondrian print, ensured that she, dressed as Mary, was sited on Sunday morning. She left an identical dress by Mary's body, burnt her own, then killed Percival with his own gun, making it look like suicide. Endeavour arrests the diva, but tragically, operatically, she hangs herself in her cell. Endeavour Morse is left with new demons to expel, an ally in DI Thursday, and a promising career as an Oxford detective.

Support Provided By: