Almost against his will he glanced from Ron to Hermione

Almost against his will he glanced from Ron to Hermione, both of whom looked devastated.

“I messed up, Harry,” said Ron bleakly. “We did like you told us: we checked the Marauder's Map and we couldn't see Malfoy on it, so we thought he must be in the

Room of Requirement, so me, Ginny, and Neville went to keep watch on it... but Malfoy got past us.”

“He came out of the Room about an hour after we started keeping watch,” said Ginny. “He was on his own, clutching that awful shriveled arm—”

“His Hand of Glory,” said Ron. “Gives light only to the holder, remember?”

“Anyway,” Ginny went on, “he must have been checking whether the coast was clear to let the Death Eaters out, because the moment he saw us he threw something into

the air and it all went pitch-black—”

“—Peruvian Instant Darkness Powder,” said Ron bitterly. “Fred and George's. I'm going to be having a word with them about who they let buy their products.”

“We tried everything, Lumos, Incendio,” said Ginny. “Nothing would penetrate the darkness; all we could do was grope our way out of the corridor again, and meanwhile

we could hear people rushing past us. Obviously Malfoy could see because of that hand thing and was guiding them, but we didn't dare use any curses or anything in case

we hit each other, and by the time we'd reached a corridor that was light, they'd gone.”

“Luckily,” said Lupin hoarsely, “Ron, Ginny, and Neville ran into us almost immediately and told us what had happened. We found the Death Eaters minutes later,

heading in the direction of the Astronomy Tower. Malfoy obviously hadn't expected more people to be on the watch; he seemed to have exhausted his supply of Darkness

Powder, at any rate. A fight broke out, they scattered and we gave chase. One of them, Gibbon, broke away and headed up the tower stairs—”

“To set off the Mark?” asked Harry.

“He must have done, yes, they must have arranged that before they left the Room of Requirement,” said Lupin. “But I don't think Gibbon liked the idea of waiting up

there alone for Dumbledore, because he came running back downstairs to rejoin the fight and was hit by a Killing Curse that just missed me.”

“So if Ron was watching the Room of Requirement with Ginny and Neville,” said Harry, turning to Hermione, “were you—?”