"Then speak. Before I delouse this world, and all other worlds."
The search for a doorway back to their own universe has taken the TARDIS crew to Boodjoori; a solar system that has been made into a computer. However, our heroes quickly discover that the system holds some very dark secrets indeed.
Inspired by the ravings of a suicidal lunatic, the Doctor, Jadi and Angela search for the meaning of his dying words, but find their quest interrupted by the appearance of mysterious black cubes with an appetite for life. Can they avoid being consumed, or have they finally had their chips?
Meanwhile, angst-ridden, lovesick and drunk out of his tiny little mind, Wil is ill-prepared to be accousted by a native with only one thing on her mind: procuring the TARDIS. Alone and unaided, can the Fool fight off her advances?
And behind this all, behind failsafe after failsafe, sits the biggest foe the Doctor has ever encountered. Alone against such a force, surely all must be lost... surely?