Detective Fantasy #15 is a combo of Amazing Fantasy #15 and Detective Comics #27.
The legendary issue that introduced Spiderbat to the world.
It starts with Comissioner Jameson chatting with his friend, Bruce Parker. A call comes to Jameson from the police department, a man has been murdered and fingerprints on the knife shows that it was the man's son. He heads over there immediately, accompanied by Bruce. When they arrive, the man's son explains that when he came home he found his father stabbed to death. He picked up the knife which is why his fingerprints were on it. While still at the crime scene, Commissioner Jameson receives a call from Steve Shiffman, one of the victim's business partners who claims there has been an anonymous threat on his life.
No sooner has Shiffman gotten off the phone with police than an armed assailant shoots him and steals a paper from his home climbing out the window to the roof with the help of a partner. The "Spiderbat" knocks one unconscious and tosses the other off the roof, and retrieves and reads the document before jumping into a car and speeding off.
Meanwhile, Ionello, one of the two surviving business partners, pays a call on Warren, the other living partner. He is admitted to the home by O'Reilly, Warren's man servant, who then suddenly and unexpectedly attacks him. O'Reilly puts Ionello in a gas chamber. Then Spiderbat arrives and breaks the chamber with a monkey wrench. O'Reilly sees Spiderbat, who then tackles him. Then Warren arrives and tries to stab Ionello, but to no avail due to Spiderbat's interference. Then Warren tries to shoot Spiderbat, Spiderbat gives a punch that knocks out Warreb
Commissioner Jameson then talks to Bruce about this case. Jameson notes to himself that Bruce Parker must have a boring life. Then you see the wealthy Bruce Parker walk into the closet and come out dressed as Spiderbat.
Can Commissioner Jameson solve the case of the Chemical Syndicate? And who or what is this man they call The "Spiderbat"?