Demon is the bloodiest love story of all. Set in Victorian London it tells the tale of Lorcan a young handsome man cursed by love that transforms him into a blood-thirsty demon.

Argentinian tango teacher Valentina Martino is not having an easy time of it. Her ex-husband evaded taxes, so she has to stay in Cornwall illegally. She lives there with her niece Elena. To earn money, Valentina works as a domestic help. However, this is not easy, as her employer Jack Rukin, who earns his living as a writer, has just been widowed. There are signs of turbulence when Henry, Jack's neighbor and arch-enemy, makes a bid for Valentina.