Malcolm Webster (Reece Shearsmith) is, on the surface, a perfect British gentleman. Well-spoken, personable, and oozing with charm, he marries his first wife, Claire Morris (Sheridan Smith), in 1993. However, a year after her dream wedding, Claire is deadthe apparent victim of a tragic road accident. Four years later, a broke Webster starts anew in New Zealand with his second wife, Felicity, who helps him to find love again. But on their wedding night she feels groggy, and for the next year suffers fromunexplained blackouts. This chilling true story tells how Felicity pieces small clues together before finally realizing that the death of Websters first wife might not have been an accident. After Malcolm disappears and resurfaces in Scotland, Felicity begins a desperate race against time to try and convince a Scottish detective (John Hannah) her husband is in fact a cold-blooded killer already lining up wife number three.