Magnum and Higgins travel to London, England to oversee the establishment of Robin Master's new castle, Robin's Keep, in time for a large banquet. While Higgins is busy training Ian MacKerras for the running of the castle, Thomas takes the opportunity to visit Geoffrey St. Clare, an old friend from Vietnam, but upon arrival, Geoffrey's wife Penelope informs him that Geoffrey has been killed, after being run down in a hit-and-run incident with a black Jaguar. But there is mystery surrounding the death - Geoffrey was supposed to be in France, and the circumstances suggest that, far from being an accident, the death was deliberate murder.The events of Geoffrey's killing seem to be echoing a disturbing, bizarre dream that Magnum had on the journey to England...