The Unicorn Girl was the middle volume of the Greenwich Village Trilogy by three different authors, the other two being Chester Anderson and T.A.
Kurland has also written two novels, Ten Little Wizards and A Study in Sorcery, set in the world of Randall Garrett's Lord Darcy, prefiguring his later success as a mystery writer.
Following the success of The Infernal Device, which was nominated for an Edgar Award (as was his earlier A Plague of Spies), Kurland turned his attention to detective fiction.
Several of his subsequent novels have been sequels to The Infernal Device, and feature Sherlock Holmes's nemesis, Professor Moriarty.
In this series, Professor Moriarty is an antihero (and sometimes a real hero) who resignedly tolerates Holmes's obsessively exaggerated opinion of his criminal empire, and is often brought into reluctant alliance with his nemesis in order to counter menaces ranging from threats to their associates to threats to the nation.