Ginny Weasley was sitting on her bed alone in her bedroom when she heard a knock on her door.
"Who is it?" asked Ginny curiously.
"Me and Hermione, " answered Harry urgently, "May we please come in?"
"But of course, " answered Ginny warmly, going over to the door and opening it to let Harry and Hermione in.
Harry and Hermione entered the room and Hermione piped up, "We need to talk."
"Come and sit down on my bed then, " offered Ginny politely.
Harry, Hermione, and Ginny sat down in a short row of three on Ginny's bed.
"So, " Hermione told Ginny seriously, "Harry and I will not be returning to Hogwarts for the 1997-1998 school year. We are going away on a mission."
"Don't tell my mom you're not going back to school, " said Ginny warningly, "And especially don't tell my mom you're going on a mission, especially if it is dangerous. You know how fussy, worried, and protective my mom can get."
"We won't tell her, " promised Harry, "But we can't tell you exactly what we will be doing on our mission. I've promised Dumbledore not to tell anyone."
"And at any rate, " added Hermione, "It's best if only we know what's up for the time being."
"I respect that, even if I can't pretend not to be curious, " said Ginny longingly, "Is that it then?"
"No, " said Harry firmly, "There's something I'm going to loan you while Hermione and I are away."
Next nanosecond, Harry retrieved the Marauder's Map from his left pocket with his left hand.
"This, " explained Harry, "Is called the Marauder's Map. It is a map of Hogwarts. When activated, it will show what everyone at Hogwarts is doing every minute and every nanosecond of every day. "
"However, " said Hermione said in a businesslike voice, "That's all it does. It'll be pretty useless away from Hogwarts. This map can be used to avoid getting caught or into trouble while at Hogwarts by showing you where Snape is, where Filch is, etc."
"OOH!" piped up Ginny with a gleam in her eyes, "This could be extremely useful for me this year!"
"Much more so than for me, " said Harry clearly, 'That's why I am lending it to you. Let me be clear. I'm LENDING this map to you but NOT giving it to you. I am lending you this map on the condition that you return it to me upon request."
"I accept those terms, " said Ginny briskly, "But how do I activate it?"
In response, Harry dug his right hand into his right pocket and withdrew his wand.
Harry pointed his wand directly at the Marauder's Map and declared, "I solemnly swear that I am up to no good."
The text about how Moony, Wormtail, Padfoot, and Prongs were proud to present the Marauder's Map now appeared.
"OOH!" cried Ginny in surprise, "James, Sirius, Remus, and the fucking traitor wrote this map?"
"Yes!' grinned Harry.
"Did you inherit this map from your dad then?" asked Ginny eagerly.
"I'd like to think it is rightfully mine, " admitted Harry, "But at one point it was confiscated from my dad by Filch. Fred and George nicked it from Filch's office in their first year. Fred and George gave me the map in their fifth and my third year so I could sneak into Hogsmeade as it also has seven secret passageways.
"Fred and George never told me about it!", said Ginny indignantly, "I'm their sister! But, I suppose you'll tell me exactly how to use it?"
"I'm showing you now, " said Harry in a businesslike voice.
Harry unfurled the map and showed Ginny the secret passageways into Hogsmeade and then explained how to see what people are up to at Hogwarts.
As there were no students at Hogwarts at the time, only staff were shown in this instant. Nevertheless, Ginny grasped how it worked seeing Sprout in Greenhouse Three, Filch in his office, and so forth.
"Now, " said Harry importantly, "Once you're done using the map, you need to wipe it clean so no one else can read it."
Harry demonstrated this by pointing his wand at the Marauder's Map and saying, "Mischief Managed!" at which point the map went blank again.
"I get it, " said Ginny clearly, "I take it that I am not tell anyone else about the map?"
""You may tell Neville and Luna, " said Harry decisively, "But no one else."
"I agree with that, " said Hermione fiercely, "Generally speaking, it's best not to tell people about the map. But, I would trust Neville and Luna in a foxhole."
"So would we!" agreed Harry and Ginny together.
Harry handed the map to Ginny and said in no uncertain terms, "For now, you are the caretaker of the Marauder's Map. But, I am still its owner."
"I understand, " said Ginny calmly, "I'm going to restart Dumbledore's Army when the next semester begins. I know Neville and Luna will be on board and I imagine that the three of us will be the leaders with you and Hermione gone. I imagine doing some recruiting and rerecruiting and it'll be useful, useful in general too, to have a tool to avoid running into people like Snape and Filch."
"That's the idea, Ginny, " said Harry matter of factly, "The map won't be of any use to me away on my mission and you can make use of it while I'm gone. Ultimately, it's still mine in the end though."
"I promise to return the map to you the nanosecond you ask for it back, " promised Ginny, "And good luck on your mission!"
A/N: I always did think that Harry should have loaned the map to Ginny while he was away on the Hunt for the Horcruxes. The map really isn't of any use away from Hogwarts so...