He wants revenge on the Russian Petrov princes (Lloyd Hughes and Wallace Macdonald) who he thinks caused the death of his daughter. After the Revolution the Petrovs are in exile in America and the mad scientist is now released from the gulag and has the help of the Bolsheviks...
He possesses jewels of the Petrovs called the Drums of Jeopardy, he promises to return the jewels to the family one by one as he disposes of them.
The jewels are cursed (naturally), it's said that if one of the drums is separated from the others whoever receives it dies within twenty-four hours...
There follows some murky goings on, some bumpings off and other evil schemes. The action isn't that great though certainly atmospheric and the acting (especially by Oland) a bit over the top but it is a fascinating film. Oland's character was Dr Boris Karlov, it's said that Boris Karloff got the idea for his screen name after reading the original novel.
