'Blood Harvest', written by Terrance Dicks, features the Seventh Doctor, Ace and Bernice.
Back Cover Blurb
'Doc's peddling bootleg liquor in an illegal speakeasy. You're carrying a gun for him, Ace - which makes you no better than any other gun-moll.'
Dekker is a private eye; an honest one. But when Al Capone hires him to investigate a new joint called 'Doc's', he knows this is one job he can't refuse. And just why are the Doctor and Ace selling illegal booze in a town full of murderous gangsters?
Meanwhile, Bernice has been abandoned on a vampire-infested planet outside normal space. There she meets a mysterious stranger called Romanadvoratrelundar - and discovers an ancient and malevolent power, linking 1929 Chicago with a lair of immortal evil.
The consequences of this story are inextricably linked to events in the Doctor's past. The full story is reealed in the first of a series of Missing Adventures - Goth Opera by Paul Cornell.