Showcase #4 was an issue of the Anthology Comic Showcase that was published on October 1956 by DC Comics. It contains two stories that star police scientist Barry Allen, the second person to become the superhero The Flash; one of the stories detail his origin story and his first adventure as a superhero. It was written by Robert Kanigher and drawn by Carmine Infantino, with inking done by Joe Kubert.
This comic is credited for reigniting the popularity of superhero comics in the mid-1950s, thus beginning The Silver Age of Comic Books in earnest.
Barry Allen was reading an issue of Flash Comics in the police station's laboratory when a freak thunderstorm rages in Central City. A lightning bolt soon strikes into the lab, hitting Barry and causing him to crash into a cabinet full of chemicals. Miraculously surviving being struck by lightning and covered in chemicals, Barry leaves his lab to go home. However, while trying to catch a cab, he manages to outrun it. Later, at a diner, a waitress accidentally drops a tray of food but Barry, watching the food fall in slow motion, manages to catch everything with incredible swiftness. Barry quickly goes home to sleep, dismissing what happened as only a dream.
The next day, when meeting with his girlfriend Iris West, Barry, with his enhanced perception, soon notices a stray bullet heading straight to her and hurls her out the way. A cop soon tells him that the stray was fired by the Turtle Man, an infamous criminal known as "the Slowest Man on Earth", while he was making a getaway. Now realizing that the accident from last night changed his molecular structure and gave him superhuman speed, Barry decides to use his newfound abilities to become a superhero much like Jay Garrick in the comics he read. Listening to the system alarm in the station, Barry releases a red-and-yellow uniform from out a special ring and rushes into action (in fact, he goes so fast, he manages to brake the sound barrier which attracts the attention of a radar station).
Barry is astounded to see that both a robbery in the Central City bank is still in progress (victims hands are still up, bank vault is open yet is untouched, etc.) and the perpetrators are no where to be seen. He soon deduces that this is the work of the Turtle Man and that he's planning to do another stage of the robbery after catching everyone off-guard by seemingly not finishing what he started. Barry tries to chase after the Turtle, but the latter manages to use the hero's speed against him at every turn. After trying and failing to reach the Turtle, who's getting away on a speedboat, Barry puts his incredible speed to more creative uses by creating a vortex in the sea, trapping the Turtle. After bringing the slow-moving criminal to justice, Barry gains plenty of media attention as he declares himself "the Flash".
Tropes pertaining to Mystery of the Human Thunderbolt
- Ascended Fanboy: Barry is shown to be a fan of the Golden Age Flash and decides to follow his favorite character's example in becoming a superhero once he receives his powers.
- Freak Lab Accident: A combination of being struck by lightning and having various chemicals spilled on him changes Barry's body structure to give him super-speed.
- Origins Episode: This story shows how Barry Allen received his super speed and how he developed his superhero identity.