Former Detective Hillary Greene and her cold case team are taking a fresh look at the unsolved murder of Michael Beck, found bludgeoned over the head and dead in a river near his home in 2012.

Just twenty-two at the time, he'd recently finished a history degree and had his whole life ahead of him. Everyone said he was a pleasant sort of lad with a passion for the past, quietly living with his parents until he could afford a place of his own. But it quickly turned out that there were at least two people who might have wanted him dead.

The first, his recently jilted girlfriend Mia de Salle, hadn't taken the break-up well. The second, his former tutor Dr Timothy Durning, had been accused of sexual harassment by Michael. But the original team could find no forensic evidence linking either of their prime suspects to the crime, nor witnesses placing them in the area when Michael was killed.

Hillary, however, is determined to find fresh leads. But while she and her team get to work, in the city of Oxford two men from the city's criminal underbelly have been viciously murdered in the last six months.

Are the recent murders and her own cold case linked? More than a decade later, has the same killer struck again? And if so, what's the connection between the mild-mannered young man and the underworld criminals?

It's up to Hillary to stop a killer getting away with murder—both now and then.