While heading through the Bat-Cave en route to the Batmobile, Batman and Robin discover a dead body in the Bat-Cave's depths. Batman determines the cause of death as a blow to the head, and Robin, identifying him as Alec Wyre, a criminal electronics genius, blurts out that whoever killed him knows their secret identities. A notebook Wyre carried gives them the names of three of his criminal "customers" who brought inventions from him: Jigger Mulane, Don Dolson, and Hank Purdy. Batman and Robin apprehend each of them in turn, and accuse each of Wyre's murder, but each claims ignorance of Wyre's death. Since a guilty man would have tried to bargain with the threat of disclosing Batman's identity, they realize they have drawn three blanks. But the manner they used to track down Hank Purdy, a