The Underground Conspiracy: Book One

Following his escape from Hogwarts, Sirius decides to take matters into his own hands regarding his godson. Reaching out to an old friend, Sirius brings the Underground, an organization known for its acceptance of society's dregs, in on the plan to rescue his godson from the Dursleys. Helped by Nymphadora Tonks, Sirius rescues Harry from his loveless life and gives him a real home.