- "Disappeared several days ago. No great loss."
- —The Monocle[src]
The Boy disappeared at the age of ten and reappears in his childhood form 20 years into the future. Only referred to as The Boy or Number Five, birth name not know or used. He appears to be capable of traveling through time under his own power, although he was forced to spend decades in the future trying to prove the possibility of backwards time-travel before he was able to achieve it. He was shown to have aged normally in the distant future, but regressed back to his youth in transit. The Boy claims to have read accounts of the Academy’s immediate future and their connection to an apocalypse.
As revealed on the Dallas storyline, Spaceboy (Number One) and The Boy are twin brothers. In the same storyline, he acquired a puppy whom he named Mr. Pennycrumb. He also revealed to The Rumor (Number Three) he was captured and "modified" by the surgeons of the Temps Aeternalis, who mixed strands of DNA of serial killers and 00.05's, making him the perfect killer with a 100% success rate, and learned him how to perform little jumps in time, thus making him incredibly fast. Technically being a sixty year old in the body of his ten year old self, we see him drinking coffee, getting drunk watching a chimp in drag sing to him Marilyn Monroe's 'Happy Birthday', taking bets at the dog races, and driving a car. It is not explained how he is legally allowed to do those things.
The child that would become known simply as Number Five was born at the same time as forty-two other extraordinary children. As a baby, he was adopted by the world-famous scientist and entrepreneur Sir Reginald Hargreeves with the express intention of training them to save the world. Number Five lived at the special academy set up by Hargreeves to train the children. Designated as Number Five by Hargreeves, the Boy had the ability to time travel. Using his abilities, Number Five travelled forward in time, disappearing several days before the Umbrella Academy's first mission in Paris to stop the rampaging Eiffel Tower. Sir Reginald indicated that his absence was no great loss.
Shortly after the death of Sir Reginald, Number Five returned to the Academy, seemingly having not aged a day since his disappearance. He revealed himself first to Phinneus Pogo, then to Spaceboy after his brother had returned from the Moon in the wake of their father's death.
- The Umbrella Academy: Apocalypse Suite
- The Umbrella Academy: Dallas
- ...But the Past Ain't Through With You
- Mon Dieu!