Sorry about the mix up.  This should be the right book.  

A serial killer is burning people alive in the Lake District's prehistoric stone circles. He leaves no clues and the police are helpless.

When his name is found carved into the charred remains of the third victim, disgraced detective Washington Poe is brought back from suspension and into an investigation he wants no part of.

Reluctantly partnered with the brilliant but socially awkward civilian analyst, Tilly Bradshaw, the mismatched pair uncover a trail that only he is meant to see. The elusive killer has a plan and for some reason Poe is part of it.

As the body count rises, Poe discovers he has far more invested in the case than he could have possibly imagined. And in a shocking finale that will shatter everything he's ever believed about himself, Poe will learn that there are things far worse than being burned alive...