Collecting the Stone and the Diadem

On the third week of January, I find myself inside the Transfiguration classroom in Hogwarts at 2 AM the morning. I wear the invisibility cloak. Kreacher is with me, invisible too.

I shrunk the vanishing cabinet and pocketed it inside my pants. I proceed to go to the third-floor corridor. With Kreacher's help, we bypass the door which is heavily charmed with tracking spells and the likes. Fluffy is sleeping. We were very quiet and down directly through the trap door. The devil snare was easily defeated by Lumos Maxima.

With my own broom, I skillfully obtained the immobilized keys and open the door. I'm careful not to use my wand to leave any magical signature behind. I'm proficient at wandless magic, so it is easy.

With my broom, I easily bypass the chess game by flying over it. In the next room, I drink my ready-potion to walk through the fire. In the last room, I wandlessly unravel the many enchantments the mirrors had. A few minutes and I have the stone.

The way back is very easy. As Kreacher already knows the way. I just asked him to disapparate us outside. All this time, we are still invisible.

Next, we go to the ROR. I plant the vanishing cabinet beside a very unassuming statue. I ward it heavily to not be seen by anyone other than me. After I obtain the diadem, we go back home.