The presence of the Death Eaters outside increased the ominous mood inside number twelve. They had not heard a word from anyone beyond Grimmauld Place since Mr. Weasley’s Patronus, and the strain was starting to tell. Restless and irritable, Ron had developed an annoying habit of playing with the Deluminator in his pocket: This particularly infuriated Hermione, who was whiling away the wait for Kreacher by studying The Tales of Beedle the Bard and did not appreciate the way the lights kept flashing on and off.
“Will you stop it!” she cried on the third evening of Kreacher’s absence, as all light was sucked from the drawing room yet again.
“Sorry, sorry!” said Ron, clicking the Deluminator and restoring the lights. “I don’t know I’m doing it!”
“Well, can’t you find something useful to occupy yourself?”
“What, like reading kids’ stories?”
“Dumbledore left me this book, Ron—”
“—and he left me the Deluminator, maybe I’m supposed to use it!”
Unable to stand the bickering, Harry slipped out of the room unnoticed by either of them.

- DH11