Philo Vance Detective: Money Machine Murder Case

A gang of conmen is selling machines that they say can manufacture genuine $1 bills. It's a neat scam, but it leads to murder! How did the traveling monogram illusion work? Frank Kent, an inmate of the state hospital has been broken out. The hospital is actually a mental institution. Frank was there because his mind is permanently in another world. But, the reason somebody wants him, is because he is a mathematical genius, he can add, subtract, multiply or divide any figure, in only a matter of seconds. And the kidnapper wants to use him as a money making freak show.