QUOTE : a baby. No wonder it meant so much to Sirius to give Harry the Firebolt. He learned that they had had a cat, that Petunia had sent a hideous vase, that James had been proud of his baby’s ability on a broom . . . ordinary things that Harry would have given anything to have in his life growing up. The letter was an “incredible treasure” to Harry, as it would have been to anyone: “He stood quite still, holding the miraculous paper in his nerveless fingers while inside him a kind of quiet eruption sent joy and grief thundering in equal measure through his veins.” (HP/DH, 181) This is blood magic, this uncontrolled rush of painful love for and from his mother flooding all Harry’s being, changing him, bathing him in the oxytocin that is the Muggle name for the magic of love flowing in the blood to create more love, to help infants grow, to hasten healing, to create empathy and protectiveness. This is what Harry craved, having known 15 months of it and then no more until he gained his friends at Hogwarts. This is what child Snape craved when he gazed greedily at Lily, who had been raised with such love. This is what Voldemort craved so badly that he didn’t even know he craved it until he saw Lily’s love for baby Harry and then the force of his craving sent him howling into nothingness, unable to regenerate a human body until he stole the oxytocin in Harry’s blood with Lily’s love still in it.