The Doctor returns to the Sensesphere many years after he helped defeat the plans of the evil City Administrator. The City Administrator was banished into the wilderness but, while alone and in constant fear for his life, he discovered a secret in the Yellow Mountains which puts the First Elder's crystal water spring to shame. With this secret he has gained control of the entire Sensorite Nation and only the Doctor can save them...

The monsters in the aqueduct have escaped - promised high office by the City Administrator in return for assisting him in a devilish plan to extract the molybdenum from the Sense Sphere.

But the Doctor will soon discover that where there is one fiendish villain hell-bent on causing mayhem and intrigue there may well be more...

The Throwback Trilogy gives fans a chance to re-embrace elements from the shows past which have an unfairly poor reputation. Matthew Waterhouse said he was "delighted" to be given the chance to breathe life into both the character first brought to our screens by the late Peter Glaze and to have his first paid acting job since the Cold War ended. We don't think there is a connection.