The Pescatons (Target Paperback Novel)

Released in 1991 as part of the Target Novelisations series (despite not being based on a TV episode). Please note that this book is over 30 years old and as such may have some light wear or discolouration to the cover, but is in otherwise good condition.
 
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.
 
Someting 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.