Gordon Way may be dead but that's not slowing him down. In fact he is attempting to finish one last vital task before departing for other levels of existence - if only he could think what that task is. He fails to make himself visible or audible to his sister Susan Way, whose boyfriend Richard MacDuff, prime suspect in Gordon's murder, has just completed a second session under hypnosis with Dirk Gently, Holistic Detective.

Whilst Dirk looks for the interconnectedness between Gordon's death, Richard's strange behaviour in trying to burgle Susan's flat and the poltergeist which appears to have invaded Richard's flat, he comes face to face with his nemesis, Detective Sergeant Gilks, and they discover incontrovertible evidence about Richard's involvement in the crime.

As Gilks is suddenly called back to Cambridgeshire to deal with an incident in a burger restaurant involving an Electric Monk and a horse, Dirk comes to the reluctant conclusion that the problems of reconciling all the elements of the case are so intractable that he must write down what the answer is. All his assistant Janice Pearce can see is childish squiggle.

But Dirk knows where to find the answer - he must return to the scene of the most impossible of all the bizarre events which have taken place so far - Cambridge University.