Inheriting a vast fortune after his parents are killed by a gangster, ten-year-old Bruce Wayne vows to avenge their deaths by spending the rest of his life fighting crime in Gotham City.
Cared for by Alfred Pennyworth, the family butler, Bruce works in total isolation and becomes a master scientist. Fourteen years later, after constructing the world's greatest crime lab beneath his home, Wayne Manor, Bruce adopts the guise of the mysterious caped crusader, Batman, a figure designed to strike fear into the hearts of criminals.
Some time later, while attending the circus with a group of orphans, Bruce witnesses a tragic accident: the death of the Graysons, a husband-and-wife high-wire act. When he discovers that the Graysons' only survivor is their teenage son, Dick, Bruce undertakes the responsibility of caring for him, and eventually becomes his legal guardian. During this time, Bruce reveals to Dick his secret alias and teaches Dick to perfect his mental and physical skills. Instilled with a desire to aid Bruce in his battle against evil, Dick adopts the guise of Robin, the Boy Wonder, and the two form the Dynamic Duo.
When Police Commissioner Gordon's beautiful daughter Barbara returns home following her college graduation, she acquires employment in the Gotham City Library, and feeling the need to help her father battle crime, she adopts the guise of Batgirl. Though operating independently, she helps form the Terrific Trio when working with Batman and Robin.
Stories relate their crusade against the sinister forces of evil that plague Gotham City.