"You're right, Potter," Snape whispered into Harry's ear, and he cringed as he felt Snape's hot breath brush against his neck. "He trusted me, trusted me to the point that I was the one he turned to to ensure his quick and painless death." Instead of leaving without explanation, Snape decides to tell Harry the secret behind Dumbledore's murder. Shocked with alarming new revelations, Harry turns to Ron and Hermione for advice. One-shot. Prologue to "Mercy-Kill II: The Horcrux Hunt."