A second chance at life

Harry is given a second chance at life in Kings Cross. Reborn as the son of Sirius Black he is on a tight schedule to bring about the end of Voldemort and his death eaters before the wizarding world is torn apart by war. Harry/Tonks maybe more. Powerful but far from invincible Harry. Includes Black family politics, and NO! Lords/Ladies OR mad shopping sprees with apartment trunks..