Sera Kentley, recently married and living in London, finds herself the victim of a stalker named The Night Watchman. At first, Sera shrugs off Night Watchman's threats but soon she must head his warning that he plans to kill her on her birthday. Although her new husband, Alex Kentley, seems supportive, he and Sera's Aunt Julie wonder if Sera is making it all up to gain attention. But Scotland Inspector Gavin Robards feels Sera's plight is all too real, and he's out to help Sera discover the identity of Night Watchman before it's too late.