In the dark uncharted depths of the North Sea it has lurked, growing in strength, growing in size, and striking terror into the hearts of mariners down the untold centuries.

Landing near a North Sea gas refinery off the east coast of England, the TARDIS crew are immediately accused of sabotage. Several rig crews have mysteriously vanished, strange pressure build-ups have been detected, and in the refinery's pipelines the Doctor can hear the steady, rhythmic beat of - what?

Soon the Doctor, Jamie and Victoria will find themselves at the unrelenting mercy of the deadliest and most terrifying foe they have ever encountered...

An invasion of meteorites and an environmental crisis! A scientific expedition has disappeared from the bed of the Thames Estuary, where a giant meteorite had landed years previously. Having landed the TARDIS in the same vicinity, the Doctor and Sarah Jane are attacked at night by a vast, roaring creature. Something reminds the Doctor of his encounter with the marine denizens of the planet Pesca, but before long his worst fears are confirmed: strange meteorites are landing all over the world, and the Pescaton invasion has begun. The Pescatons, starring Tom Baker as the Doctor and Elisabeth Sladen as Sarah Jane Smith, was released as an LP record in 1976, and re-released in 1985.

Victor Pemberton, who wrote the original script for the LP, has been variously scriptwriter, script editor and novelizer of several Doctor Who television stories.