Antidote to Oblivion (Doctor Who)

Future Britain is bankrupt, its corporate owners facing financial ruin. Fortunately, the Universal Monetary Fund, and its slimy representative Sil, are willing to give its President a multi-billion credit bail-out... but terms and conditions apply, and Sil's proposed austerity measures go far beyond mere benefit cuts. Responding to a distress call, the Doctor and his companion Flip land in a London whose pacified population has been driven largely underground. But the horrors down there in the dark are as nothing to the horrors that await them at ConCorp HQ, where a young biochemist in Sil's employ is working on a permanent solution to the nation's terminal unprofitability. Because in the final account, Sil plans to make a killing...