'A Device of Death', written by David A. McIntee, features the Fourth Doctor, Sarah Jane Smith, and Harry Sullivan.
Back Cover Blurb
'As a member of an inferior race, you either work to serve the cause of Averon, or die.'
Sarah is marooned on a slave world where the only escape is death. Harry is caught in the middle of an interplanertary invasion, and has to combine medicine with a desperate mission. And the Doctor lands on a world so seret it does not even have a name.
Why have the TARDIS crew been scattered across the stars? What terrible accident could have wiped the Doctor's memory? And what could interest the Time Lords in the war-torn sector of space?
At the heart of a star-spanning conspiracy lies an ancient quest: people have been making weapons since the dawn of time - but perhaps someone has finally discovered the ultimate device of death.