Sirius Black had entered Hogwarts!
The news came from the Fat Lady, who was hiding in another portrait.
A murderer had infiltrated Hogwarts—this was far more terrifying than last year's rumors about the Chamber of Secrets.
At least the Chamber of Secrets had been more like an urban legend.
But a murderer was a real murderer.
He was incomparably vicious, and had even blown up everyone on an entire street.
"All students will sleep in the Great Hall tonight. The teachers will take turns standing watch while we search the castle floor by floor."
In the end, Dumbledore came up with the decisive plan.
No matter what, Sirius was only one person. Every professor at Hogwarts was an exceptionally capable wizard, and with the advantage in numbers, they truly had no reason to fear Sirius.
The only trouble was how to find him.
With so many students sleeping in the Great Hall, packed tightly together, everyone actually felt safer.
However, Prince Su and the other nine members of the Gryffindor squad quietly tied all their blankets together, then ducked their heads underneath and began plotting something inside.
They came up with several plans.
How to provide support, how to gain his trust, how to rescue Sirius if he failed, and so on.
Harry was also hiding beneath his blanket, using the Marauder's Map to observe something.
With this thing, it would be easiest to find Sirius!
The moment he found him, he would tell the professors.
Yet no matter how hard he searched, he could not find Sirius's name on it. Instead, he saw another name that should not have been there at all!
"Peter Pettigrew?"
Harry remembered that name. He had been his parents' companion, the one supposedly killed by Sirius.
He should have been dead!
Why was he