Missing Persons

Hannah Grant had volunteered to cover Alan Gregory's practice over the Christmas period, but when he and another colleague called at her office they discovered her body, the cause of death not clear. Then on Christmas Day itself a fourteen-year-old girl is reported missing - eight years to the day after another missing child had been discovered murdered - a girl who had she lived would have been fourteen.
Then it emerges that the parents of the latest missing girl had been treated by Alan some years ago, and recently the girl herself had consulted Hannah. Could any of these tangential connections prove to be links to both deaths and the missing girl, or are they mere coincidences? And should Alan break the seal of patient/doctor confidentiality if the few strands of knowledge he has can throw light on any of these mysteries?