They're a bit younger in this than I've been drawing them. From the AU in my head where they were friends. I imagine Harry just said something oh-so-dramatic and heroic, and Draco's about two seconds away from laughing at him for it.
... How cute are Draco's hiked-up trouser-legs? Inspired by the scene in the HBP movie when Harry and Luna walk by Draco sitting in an alcove in the hallway on the way to Slughorn's party.