Summary The scientist-inventor of the “ray of life” is found murdered. The perpetrators are Arachni (=Spider) and the inventor’s former assistant, Mona. The formula of his invention, however, was taken by the man’s two naïve servants, Kokkovios and Sparos. Arachni and the rest of the gang keep setting up traps to obtain the much-desired paper from the two dummies - but to no effect. In the end, the gang falls into the hands of the police, and the celebrated paper proves to be nothing more than common grocery bills.