Defeated in The Gates, Satan — in the form of the terrifying Mrs. Abernathy — returns to take vengeance against Samuel Johnson and his friends, including his faithful dachshund, Boswell, the minor demons Nurd and Wormwood, and the uniquely destructive Mr. Merriweather’s Elves.
This book is titled The Infernals in the US market, and Hell's Bells elsewhere.