Guest Stars John Simm as The Master Adjoa Andoh as Francine Jones Gugu Mbatha-Raw as Letitia "Tish" Jones Reggie Yates as Leo Jones Alexandra Moen as Lucy Saxon Trevor Laird as Clive Jones Zoe Thorne voices Sphere John Pirkis voices Sphere Gerard Logan voices Sphere Tom Ellis as Tom Milligan Ellie Haddington as Professor Docherty Natasha Alexander as Woman Tom Golding as Lad
