Draco rolls his eyes and turns his attention back to his book. Esme continues across the lawn with Draco's wand in front of her. It has a detection charm for some dittany. Brewing the essence of dittany would take a measurable time, and hopefully, when done, it would work to prevent the Dark Mark from turning into a dark rash. She had to be quick. The black veins in his arms had already moved to his elbow. She didn't want to waste any more time.