College student Merlin Jones, constantly involved with mind experiments, devises an electronic helmet that when connected to an electroencephalographic tape records mental activity. Wearing the helmet while driving, he is stopped by traffic officer Muller and brought before Judge Holmby, who suspends his license. Returning to his laboratory, Merlin discovers accidentally that his equipment enables him to read minds. Judge Holmby visits the coffeeshop where Merlin has a part-time job, and through his powers Merlin discovers that the judge is planning a crime. He rushes to the police with the information but is brushed aside as a crackpot. Merlin and Jennifer, his girl friend, break into the judge's home looking for evidence but are arrested by the police. The judge confesses that he is the popular detective novelist Lex Fortis, and requests that this identity remain a secret. Merlin's next experimentation involves hypnotism. After successfully hypnotizing Stanley, the laboratory chimpanzee, into standing up for his rights against Norman, his bullying keeper, Merlin brawls with Norman, and as a result he is brought again before Judge Holmby. Fascinated by his experiments, the judge enlists Merlin's aid in devising a plot for his next mystery. Working on the assumption that no honest person can be made to commit a crime against his will, Merlin hypnotizes the judge and commands him to steal Stanley. Surprised when the judge actually commits the crime, Merlin and Jennifer return the chimp but are themselves charged with the theft. Unaware of his part in the crime, the judge sentences Merlin to jail. Jennifer, outraged at the injustice, convinces Judge Holmby of his own guilt, and he admits that perhaps there is a little dishonesty in everyone.
