Death in Paradise star Ardal O'Hanlon has discussed the reasons for his departure.. Death in Paradise's Ardal O'Hanlon might be a hit with fans after replacing Kris Marshall, but the actor and comedian is worried that he may soon suffer the same fate as his predecessor.. He's set to return as DI Jack Mooney in the brand new series of Death in Paradise, but, sadly for fans, it'll be the last for actor Ardal O'Hanlon as he will be leaving the show. Siobhan Mooney (pronounced Shivaun) appears in 4 episodes of Death in Paradise (6:6 Man Overboard - Part Two until 7:1 Murder from Above).She is played by Grace Stone.. She is the only daughter of Jack Mooney.Siobhan takes care of her father and worries over him. Death In Paradise has been compared to Doctor Who in recent weeks, with the cast becoming a revolving door of faces. Ardal O’Hanlon has dropped hints at how and when he’s leaving Death in Paradise. Death in Paradise originally starred Ben Miller’s DI Richard Poole, but he was replaced by Kris Marshall’s DI Humphrey Goodman, who was in turn replaced with Ardal O’Hanlon’s DI Jack Mooney. She travels to Saint Marie with him on holiday, and he asks her whether she wants to make it a permanent home.