Guest Stars Tom Mothersdale as Gabriel Defoe Synnove Karlsen as Polly Hillinghead George Parker as Henry Ashe Nicholas Farrell as Chief Inspector Paxman Gabriel Howell as Elias Amy Manson as Charlotte Hillinghead Nitin Ganatra as Ishmael Oscar Coleman as Jawad Natalie Gavin as Sarah Mannix Michael Shaeffer as Hayden Harker Michael Byrne as Old Mullins John Alastair as Commander Brown Alfie Tempest as Sam Stuart Boother as Hodges Claire Jones as News Reporter Tony Lucken as Boat Captain Ben Addis as Chandler