In Victorian London, the fates of physician Simon Bell and apothecary Gaelan Erceldoune entwine when Simon gives his wife an elixir created by Gaelan from an ancient manuscript. Meant to cure her cancer, it kills her. Suicidal, Simon swallows the remainder-only to find he cannot die. Five years later, hearing rumors of a Bedlam inmate with regenerative powers like his own, Simon is shocked to discover it's Gaelan. The two men conceal their immortality, but the only hope of reversing their condition rests with Gaelan's missing manuscript. When modern-day pharmaceutical company Transdiff Genomics unearths diaries describing the torture of Bedlam inmates, the company's scientists suspect a link between Gaelan and an unnamed inmate. Gaelan and Transdiff Genomics geneticist Anne Shawe are powerfully drawn to each other, and her family connection to his manuscript leads to a stunning revelation. Will it bring ruin or redemption?