Its just to say that no-one has come to pick Nathan up from school & we were wondering if there was a problem of some kind? As Mark Douglas photographs a pod of whales stranded in the waters off Edinburghs Portobello Beach he is called by his sons school: his wife Lauren hasnt turned up to collect their son. Calm at first Mark collects Nathan & takes him home but as the hours slowly crawl by he increasingly starts to worry. With brilliantly controlled reveals we learn some of the painful secrets of the couples shared past not least that it isnt the first time Lauren has disappeared. & as Mark struggles to care for his son & shield him from the truth of whats going on the police seem dangerously short of leads. That is until a shocking discovery...