In 1995 Glasgow couple Darren and Frances Jenkinson suffered a terrible tragedy when their 2 month-old son Aaron died of a rare congenital heart defect. Or at least thats what the post-mortem concluded. Four years later, after undergoing fertility treatment, Darren and Frances managed to conceive again. But aged just 3 weeks, second son Jacob died in exactly the same circumstances. Suspicious hospital staff alerted the police to this unlikely coincidence, and detectives then unearthed disturbing signs that Darren might be responsible...