Police forensic scientist, Barry Allen, and his wife, Picture News reporter, Iris West, are out shopping. While West browses in a jewelry store, Allen spends some time, out on the street, taking pictures with his new camera. Allen is stunned to see his old childhood sweetheart, Daphne Dean, step before his lens. Allen is drawn away, from pursuing Dean, by West's screams, coming from the jewelry store. Allen investigates, as the Flash. Inside the jewelry store, the Flash confronts his old arch-nemesis, Heat Wave. Heat Wave's Hot Rod Distortion Beam disorients the Flash, causing him to stumble and fall. Heat Wave levels his weapon on the Flash.
Rather than getting up off the floor, the Flash rolls, at super-speed, into Heat Wave, rendering the fiery felon unconscious. Intent on getting back to Dean, the Flash doesn't wait around to be thanked. Dean, though, is long gone. Back at home, the Flash, as Allen, reminisces about Dean, with West. Dean's doctor calls on the Allens. Dean has recently suffered a bout of amnesia. As Dean has no family to speak of, it is the doctor's hope that her close relationship with Allen will aid in Dean regaining her memory. Allen readily agrees to spend time with Dean, though West seems a tinge jealous over the matter. The Allens' next-door neighbor, Barney Sands, watches Heat Wave's arrest on television.
Sands imagines a second encounter at the jewelry store, one wherein the Flash loses a fight with Sands' latest creation, Master Villain. Sands' older brother, Larry, enters the room, breaking Sands from his reverie. Sands shows his brother his latest illustration, a full figure study of Master Villain. Dean arrives at the Allens' home. Unbeknownst to dean, she does not arrive alone. An invisible, gaseous alien has traveled with her, seeking new experiences. The alien is drawn to Sands' powerful imagination. With Sands fast asleep at his drawing table, the alien infuses itself with the drawing of Master Villain. Sands awakens for dinner, never noticing that his Master Villain drawing is gone.
The Allens escort Dean around Central City. Suddenly, a trio of police officers goes hurtling through the air over their heads. Allen, moving faster than the eye can see, puts on his Flash costume, then vibrates down through the street, into the sewer. Having plotted the officers' trajectory, the Flash races along underground, before burrowing his way up into a nearby park. There, the Flash generates an air cushion, at super-human speed, to break the officers' fall. The officers inform the Flash that a new criminal, calling himself "Master Villain", is attacking police headquarters. Sands returns to his drawing board to discover the absence of his drawing. The Flash confronts Master Villain.
His new adversary opens by slamming his fists together, generating a massive thunderbolt. The Flash barely manages to dodge the lethal lighting strike. Master Villain leaps into the air, and literally stomps police headquarters flat. The Flash charges Master Villain, only to be possessed by his newest adversary. Master Villain forces the Flash to run, ever faster, in place, in an attempt to exhaust the Scarlet Speedster. The moment Master Villain relaxes his control, the Flash begins spinning like a top. Unable to cope with the dizzying effects brought on by the Flash's centrifugal force, Master Villain exits the Flash's body. With Master Villain still reeling, the Flash tries to put him out.
The Scarlet Speedster is so exhausted though, that his blow is incredibly feeble. Master Villain flees, leaving the Flash to puzzle over the criminal's childlike speech patterns. Dean places a phone call, and indicates that her scheme is going according to plan. Allen completely believes in her "amnesia". After hearing reports of the Flash's battle with Master Villain, Sands sits down at his drawing board, and begins to draw the only hero who could possibly bring Master Villain to justice.