Dying Fall, (Ruth Galloway #5) by Elly Griffiths; 2014. Softcover.

When Ruth Galloway learns that her old university friend Dan Golding has died in a house fire, she is shocked and saddened. But when she receives a letter that Dan had written just before he died, her sadness turns to suspicion. The letter tells of a great archaeological discovery, but Dan also says that he is scared for his life. Was Dan’s death linked to his find? The only clue is his mention of the Raven King, an ancient name for King Arthur. When she arrives in Lancashire, Ruth discovers that the bones reveal a shocking fact about King Arthur—and that the bones have mysteriously vanished.

The case draws in DCI Nelson, determined to protect Ruth and their eighteen-month-old daughter, Kate. But someone is willing to kill to keep the bones a secret, and it is beginning to look as if no one is safe.