Mathew Baynton Thomas Thorne , Plague Victim Creator, Actor, Executive Producer, Writer Simon Farnaby Julian , Plague Victim Creator, Actor, Executive Producer Martha Howe-Douglas Lady Button , Plague Victim Creator, Actor, Executive Producer Jim Howick Pat , Plague Victim Creator, Actor, Executive Producer, Writer Laurence Rickard Robin the Caveman , Plague Victim , Headless Humphrey's Head Creator, Actor, Executive Producer Ben Willbond The Captain , Plague Victim Creator, Actor, Executive Producer Charlotte Ritchie Alison Actor Kiell Smith-Bynoe Mike Actor Lolly Adefope Kitty , Plague Victim Actor Katy Wix Mary , Plague Victim Actor Yani Aleksandrov Headless Humphrey's Body Actor Ania Marson Old Lady Heather Button Actor Ed Kear Dave Houses Actor Richard Durden Solicitor Actor Anya McKenna-Bruce Jemima Actor Steve Oram Terry Actor Alison Carpenter Executive Producer Debra Hayward Executive Producer Alison Owen Executive Producer Matthew Mulot Producer Tom Kingsley Director