It was the day after Sirius Black's second break in and Harry Potter was the last to leave his dorm in the morning.
He was looking at the Marauder's Map with some trepidation.
Back in December when Fred and George had given him the map, Harry had been excited about the prospect of actually going into Hogsmeade and there didn't seem to be anything particularly sinister about the map.
But, now, after Black's second break in, it felt different.
Harry knew now that he needed to inform a teacher of the existence of the Marauder's Map and turn it in.
Not only could he not afford to risk the map somehow falling into Black's hands, but it now occurred to Harry that, in the hands of a competent adult, this map might even lead to the capture of Sirius Black if said adult understood how the map worked. Harry would have to explain that, but who could he tell?
Certainly not Snape, that went without saying.
Not his head of house McGonagall either. Telling McGonagall would only get himself, Fred, and George in trouble and McGonagall wouldn't take his actual concerns seriously.
Then it occurred to Harry: Professor Lupin.
Lupin was competent, trustworthy, and a good listener.
So, Harry walked to Professor Lupin's office and knocked on the door.
"Who is it?" asked Lupin cautiously.
"Harry Potter, and there's something you need to know, " said Harry urgently.
Lupin opened the door and saw Harry holding the Marauder's Map. Lupin recognized the Marauder's Map at once.
"It's about the Marauder's Map, " said Lupin matter of factly.
"You've seen this map before?" Harry asked Lupin.
"Yes, " said Lupin calmly, "And I know how to work it. I presume you have come to turn it in?"
"Yes, " said Harry simply.
"Harry, " said Lupin proudly, "I don't care how you came to be in possession of this map, but I am proud of you for turning it in. I'm guessing you realized the danger of this map accidentally slipping into Sirius Black's hands and realized you'd better turn it in to a teacher?"
"That's part of it, " explained Harry, "But the other part of it is that, in the hands of a competent adult, this map could lead to the capture of Sirius Black. Since you are that competent adult, and since you know how to work the Marauder's Map, you are the perfect person to keep an eye on the Marauder's Map and see if Sirius Black turns up here again."
"I will be doing that, " promised Lupin, "I'd ask why you didn't go to your head of house, but I know firsthand how useless McGonagall is."
"At this point in time, it is far better for a teacher to be in possession of this map than for me to be. That simple, " said Harry in a crystal clear voice.
"Thank you, Harry, for doing the right thing and turning this map over to me for the time being. I think it's highly likely some good will come of it."
"So do I, " replied Harry.