Ann Darrow O'Brien was the young, smart, and wealthy daughter of an eminent scientist and explorer who, at the start of the series, had disappeared two years ago and left his daughter and her assistant Akiko Oki living in his palatial Bay Area estate. To the surprise of many, the young Ann had been keeping the estate solvent. But in the first story, Ann's amoral half-sister Oniko (who left the family 15 years earlier to join a mysterious criminal enterprise) and her two henchmen enter the estate to take it over. The sisters have a brawl in an unused dimensional transportation chamber, and Ann accidentally hits a button that kicks off a "life form retrieval beam." The chamber explodes as it summons the giant, simian genius Axewell Tiberius, who's combating an unknown, apelike enemy. The henchmen escape with Oniko and the still-alive head of that enemy, while Ann and Akiko befriend Tiberius and give him a place in the estate's library.
O'Brien discovers that the blast in the chamber had released a mysterious radiation that affects both her and Oniko. Immediately after the explosion, her eyes turn orange -- the same color as Tiberius's. The next night, she needs almost no sleep to feel refreshed. The next day she finds that her sneakers no longer fit her feet: "I was growing faster than a teenager!" She performs better and better at physical tasks, lifting tons of free weights and at one point making a 60 mile run in 30 minutes without much effort. She frets a little about the ongoing growth spurts (wasting plenty of money on clothes that become too small in 24 hours), but finally settles in at seven feet tall and 250 pounds.
One adventure involved Ann being hit by Monkeyman's Bio Mass Argumenter causing her to grow infinitely. She grew so large that she dwarfed the galaxy.