He was never truly gone, only biding his time... Late on midsummer's night there is a splash in the river Thames. A body is found on an island, asphyxiated and laced with strange markings. For DCI Craig Gillard it's a baffling case. The victim's identity is elusive, clues are scarce and every witness has something to hide. Meanwhile one of Britain's deadliest serial killers is finally up for parole after a deal to reveal the location...