• 
  Rupert Graves

  Mark Bretherick
• 
  Geraldine Alexander

   Professor Fox (2 episodes, 2012)
• 
  Eva Birthistle

   Ruth Blacksmith (2 episodes, 2012)
• 
  Darren Boyd

  Simon Waterhouse
• 
  Elly Fairman

   Esther Taylor (2 episodes, 2011)
• 
  Tom Goodman-Hill

  Steve Harboard
• 
  Claudia Harrison

   Cordy O'Hara (2 episodes, 2011)
• 
  Seeta Indrani

   Dr. Chaudry (2 episodes, 2011)

• 
  Ralph Ineson

  DC Colin Sellers
• 
  Peter Wight

  DI Proust
• 
  Olivia Williams

  Charlie Zailer
• 
  Geoffrey Streatfeild

  Jonathan Hey
• 
  Emily Beecham

   Mary Trelease (2 episodes, 2012)
• 
  Amy Beth Hayes

   Sally Thorne (2 episodes, 2011)
• 
  Christina Chong

   DC Amber Williams (2 episodes, 2012)

• 
  Theo James

  Aidan Harper
• 
  Emily Olivia Robins

   Oonagh O'Hara (2 episodes, 2011)
• 
  Rick Warden

  Geoff Linton