No need to look any further

Professor McGonagall did not immediately say anything else when she saw Gavin.

Wind swept through the broken window on the fourth-floor corridor, stirring a short length of snapped rope on the floor. Six suits of armor leaned crookedly against the wall. Two had already lost their heads, while the others still held their swords, as though ready to finish what they had started.

The portrait that had been knocked down lay on the floor.

The shepherd in the painting peered out from behind the trees in a distant portrait. Once he confirmed that Professor McGonagall had arrived, he finally dared to take a few steps back.

After a long while, Professor McGonagall slowly exhaled and composed herself.

"Now, would someone kindly explain exactly what happened here?"

Four people spoke at once.

"It was Dobby—"

"We caught the Music Box—"

"Gavin prepared—"

"The first valid signal appeared at sixteen eleven and twenty-four seconds."

Professor McGonagall raised a hand.

Every voice stopped at once.

Only Ron managed another half sentence. "—a detection device."

Professor McGonagall immediately looked at him.

Ron shuddered, hiccupped, and swallowed the rest of his sentence.

"Mr. Macmillan." Professor McGonagall made her choice among them. "You have a record. You explain."

Ernie immediately unrolled the parchment that had been slashed by a sword.

"...At six eleven and twenty-four seconds this afternoon, the suspect entered the fourth-floor corridor carrying a black Music Box. At six eleven and thirty seconds, Mr. Potter identified the target as the house-elf Dobby... Mr. Gu persuaded the target to put down the Music Box, and Miss Rowle retrieved it."

Professor McGonagall was already frowning.

"Continue."

Ernie looked down at his notes.

"At sixteen twelve and three seconds, Dobby attacked... At sixteen twelve and forty-one seconds, Mr. Weasley was suspended from the ceiling... At sixteen thirteen