F ~ Fall of the House of Gryffen, The - 2010 story from Series 1 of spin-off show K-9.
Starring John Leeson as the voice of "K-9 Mk. I", Keegan Joyce as "Starkey", Philippa Coulthard as "Jorjie Turner", Daniel Webber as "Darius Pike", and Robert Moloney as "Professor Alistair Gryffen".
Darius, Starkey and Jorjie spend a very spooky night at the Gryffen mansion. June gives Jorjie permission to stay until a violent storm passes. Gryffen has been working on the Space-Time Manipulator and a bolt of energy starts up the machine and brings spectres from Gryffen's past materialising in the mansion causing mayhem. K-9 sees the ghosts for what they really are and the group have to convince Gryffen before the youngsters life forces are drained away so that the alien beings can take psychical form.
- In this story K-9 plays chess against Starkey. K-9 has previously played chess against the Doctor in the Doctor Who 1977 story The Sun Makers.