The rise of Flynn Rider / Jen Calonita.

Enhanced descriptions from Syndetics:

Before he was a legendary thief, he was just a boy named Eugene..."hi, how ya doin'?"

Twelve-year-old Eugene Fitzherbert needs a plan. He loves Miss Clare and the boys at the orphanage, but he's not a little kid anymore. He can't spend his days getting into mischief and acting out his favorite passages from the Flynnigan Rider novels. In his imagination, he is that daring rogue Flynn Rider, and his best friend, Arnie, is famous thief Lance Strongbow, who steals from the rich and gives to the poor. Even though Eugene knows it's just a fun game, he can't help but wish there was more for him out there. Travel. Riches. And maybe, just maybe, his parents.

So when a traveling circus comes to the kingdom promising a life of excitement, brotherhood, and unimaginable treasure, Eugene and Arnie see it as the start of their great adventure. But it soon becomes clear that there's more to this ragtag crew than meets the eye, and it'll take new heroes-namely, Flynn Rider and Lance Strongbow-to save the day.

Filled with daring adventure and rollicking fun, the Lost Legends series explores the untold origins of Disney's most infamous rogue boys.