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Option Lock

Author	Justin Richards
Series	Doctor Who book: Eighth Doctor Adventures
Release number	8
Subject	Featuring: Eighth Doctor Sam
Publisher	BBC Books
Publication date	February 1998
ISBN	0-563-40583-X
Preceded by	Kursaal
Followed by	Longest Day

Option Lock is an original novel written by Justin Richards and based on the long-running British science fiction television series Doctor Who. It features the Eighth Doctor and Sam.

The Doctor and Sam land in present-day England on the ancestral home of the Silver family. However, the house holds clues to a dangerous centuries-old society and something that drove a man to suicide. Unravelling this will take Sam and the Doctor through time and space to save Earth from nuclear fire.

• Option Lock title listing at the Internet Speculative Fiction Database