Sarah Jane Smith: Test of Nerve

In 2002, Sarah Jane Smith: Test of Nerve was released by Big Finish Productions.

Cover blurb
GERM WARFARE TRIALS HELD ON SIXTIES TUBES

Sarah Jane Smith receives a mysterious gift with a cryptic message. The London Underground will suffer an horrific terrorist attack during rush hour unless Sarah can find and stop those responsible. As rush hour draws closer, the terrifying reality of the threat becomes all too apparent. One friend is murdered and another is abducted. Sarah must be willing to sacrifice everyone and everything she holds dear to save the city. This is one deadline she simply cannot miss...