No Way Out by Cara Hunter

From Cara Hunter, author of the New York Times bestseller Murder in the Family, comes book three of her DI Adam Fawley series, one of Britain's most enduringly popular and mega-selling crime series. Fawley investigates a ghastly house fire on Christmas Day launches an investigation that shocks a community.
It's one of the most disturbing cases DI Adam Fawley has ever worked.
It's Christmas in Oxford, and firefighters have pulled two children from the smoking ruin of their home. The mystery deepens when it becomes clear that the parents are nowhere to be found. Why were the children left in the house alone? Why is neither parent answering their phone? Were they kidnapped? Murdered? From the start, DI Fawley—still reeling from his own personal tragedy—knows that this house fire is the scene of a crime, not an accident.
Then new evidence comes to light and confirms the team's worst suspicions. The blaze was arson. Who would have torched a seemingly happy family's home on Christmas?
As DI Fawley and his team of detectives sift through the evidence, old tensions and new problems in the family are slowly revealed. Something terribly out of the ordinary has happened, and the truth slowly begins to reveal itself...
A gripping and provocative tale of arson, murder, and family intrigue, No Way Out is everything you'd expect from one of Britain's queens of crime, Cara Hunter.