Guest Stars Toheeb Jimoh as Marcus Ursula Holliday as Cass Stewart Pete MacHale as Leon Anneika Rose as Natalie Milly Thomas as Sara Hoyt Anson Boon as Anton Garin T'Nia Miller as Charlie Morris Steven Elder as Doctor (Asylum) Milo Twomey as Scientist Alex McNally as Photographer Neran Persaud as Head of Indian Feed Beverly Longhurst as Pam (Call Centre Agent) Robert Goodman as Johnny Joshua Pulleyn as Hooded Figure