Found, Not Lost

HPDM; Harry took a wrong turn out of Borgin and Burke's the summer before his second year and got lost in Knockturn Alley. Years later, Draco Malfoy stumbles across a green-eyed rent boy on a London street corner. Who is he, and how did he get there? Will Harry Potter ever return to the world at large? Set in a world where Harry defeated Voldemort completely in his first year.