Shell House detectives mystery

"Late one night, a distraught young man knocks on the door of retired and recently widowed Ally Bright's remote home on the Cornish coast. But before she can make sense of his confused words, he's gone--not to be seen again until he's found the next morning at the foot of the nearby cliffs. In an instant, the peace of Ally's beachcombing life is shattered. Feeling responsible for the young man's fate, she wants to help find answers--as does ex-cop...