From England to Egypt, accompanied by his elegant and trustworthy sidekicks, the intelligent yet eccentrically-refined Belgian detective Hercule Poirot pits his wits against a collection of first class deceptions.

The Doctor, Romana, Adric and K9 encounter the enslaved time-sensitive Tharils, who lead them to a white void occupied only by the ruins of an old building and a spaceship - a dimension that might be the key to escaping E-Space.