If I want to go past the Cerberus and discover what the two professors discussed with such intensity, first step is to read up about the thing. Finding relevant information might be tricky as supposedly Quirrell didn't figure it out for 4 months. Still, I can't just go in and butcher the doggy, that would leave clear sign that something is up. And it's not like that would be an easy task in close quarters, that room isn't the great hall level of spacious. I could try just walking by it, but is that wise to not be prepared? There were no doors there if what little glance I got is any indicator. Magically hidden path maybe?

[Headmasters office]

Albus Dumbledore was staring out the window; moon clearly visible on the cloudless sky.

I know young Harry took interest in the forbidden corridor but that alone is not enough. To make sure Voldemort won't actually get the stone I have to hide it in the The Mirror of Erised. Using any lesser magic won't stop Tom, he's way too brilliant for common spells. The trick is to show Harry to the mirror in such a way that he thinks it's a complete coincidence. After he stares at his deepest desire, definitely a loving family, he will seek it again and then I will confront him and explain I have to move it elsewhere. When he faces his prophesized nemesis he will know what to do.

A sound like an old alarm clock wakes Headmaster from his musing.

Finally there. I will give him a day or two. With that thought old wizard retires for the night.

[]

Damn, why would you enchant a book like that? Looks like Filch got tired of finding mess in the hallways and nobody to blame. After unfortunate accident in the restricted section I find myself running away even though I am supposed to be undetectable.

First, a book trips some security measure and lights up whole library.

Then as I try to leave, lights somehow seems to follow me. Must be some form of detection mechanism. Movement sensors?

Filch chasing my trail is one thing but Snape showing up and spamming spells at every corner is whole other level of nuisance. How did he get here that fast anyway? Some of the spells I recognize as dispels, they won't work, but others are unknown therefore dangerous.

"How many!?" – screams darkly clad professor.

"Just one!" – responds Filch with smile on his face, glad that someone is going to get it this time.

Numerous manoeuvres around the shelves later I am at the exit. Suddenly light flies past me. Turning around I notice Snape charging straight at me. Couldn't have seen me, how did he… ward. Side stepping behind the nearest bookcase, I watch potion master and the janitor spin around trying to catch the invisible intruder.

Snape must have trapped every exit. Removing the detector will still cause him to notice that it has been destroyed, nullifying the point of destroying it. All I can do now is rush past and leg it as fast as I can.

Running at full speed through the side entrance I fly into the hallway.

"There!" – points Snape.

"You are done for!" – threatens Filch running faster than man his age should be able to.

After two corners I slide into the classroom. Weird, why not just run to the tower? I could easily make it, it's not like they can detect me past their little ambush. I feel drawn here, like I want to be here, what is this feeling?

Taking a step further I see a big mirror, twice my size. There is an inscription on it; "Erised stra ehru oyt ube cafru oyt on wohsi".

My, what a mind boggling mystery! I show not your face but your heart's desire. Why is this magic mirror in this random classroom? Of all the places in this massive castle I happen to wander right into the one with this in it. And it's not like I wanted to be here. I got a bad feeling about this. Time to leave.

[]

Following night it's another trip to the library. Technically yesterday's failure wasn't a failure. I wasn't caught and they have no clue who I am. However if I don't show up again they might think they scared me off and get their ego boosted. I refuse to be a source of that. From today onwards I will leave a sign that I was there but not only they couldn't caught me, they also fail to notice till I informed them of it. That will put them in place.

While I was thinking of a creative ways to anger both janitor and the master brewer I heard a whisper.

"Harry? You here?"

Ginger head peered from behind the suit of armour.

Taking sound proofing off I respond.

"You know well I am."

"You busy?" – asks twin.

"Kind of."

"Hungry?"

"What's this all about?" – I respond annoyed.

"Follow."

I jog behind the twins while they lead me down the stairs to the painting of various fruits. After one of them touches the pear a handle is revealed.

"Welcome to the kitchens." – they declare simultaneously and open the painting that is actually a door.

Inside a whole army of house elves can be seen working, carrying dishes, cleaning. Whole room is the size of a great hall and have the same tables placed in the same positions.

"We are under the great hall." – I state after thinking of the rout we took.

"Indeed Harry. How about we eat something while you tell us about yesterday?"

"What?"

"We saw you playing around with Snape and Filch in the library. Just happen to check the map, we weren't spying or anything, no worries."

I tell them of janitor's frustration and Snape's involvement.

"Figures they would step up their game." – says one of the twins.

"Yeah, we left quite a mess in the forbidden corridor. When I say we I mean you Harry." – adds the other one.

"Whatever. Say, you know how one could peacefully get past Cerberus?"

"You are going there again! Why!"

"I just happen to have some new information and am curious."

Twins look at me with anticipation. I respond with a questioning shrug.

"Tell us the info!" – they stand up with excitement.

"You don't want to know, it might end badly."

"Well, now we have to know!"

"It turns out the dog isn't why it's forbidden to go there. Apparently there is something hidden there and dog is just one of the things guarding it." – I give them little bit of the story.

"More monsters!?"

"No clue."

"Well if its monsters you are interested in, Hagrid might know. He's into dangerous beasts."

"Yes, the dog is his."

"WHAT!" – if they were sitting they would stand up again.

"Do you know Hagrid? You said he's into dangerous beasts. Is that a common knowledge."

"Not really. We went couple times into the forest to gather some unique herbs they won't sell us in the alley. Got caught couple times."

"Could you ask him about the dog?"

"Then he would know we know and we kind of aren't supposed to know."

"But he's used to you lurking around. Staff probably suspects you for all the crap I did anyway."

"Not probably! They really do! Got told off by McGonagall already." – state the twin with a hint of anger.

"Can you do it or not?"

"We can, but what can you give us for it?" – sitting down twins got into the business mode.

"How about I tell you which book has useful stealth related spells in it?"

"We already know this stuff."

"And yet you still make noise whenever you move. You found out I have a cloak but that doesn't explain how you couldn't hear me, right?"

Twins give each other the look and then nod.

"Deal."