The Lines

For DS Liam Kilshaw, a former marine who almost died on a mission gone wrong, returning to the sea was meant to help combat his PTSD. But when he’s called out with the lifeboat crew off the rugged Cornish coast at night, the dark danger of the waves comes crashing back. The body of a young man is floating in the water, and the zip—tie marks on his wrists show this is no tragic drowning—it’s murder.

It’s not the first suspicious death to...