Tom is holding your captive in the Chamber, he enjoys that situation way too much, this sense of power he now had over you, his prisoner... He didn't have to explain to you his motives, what he did or was planning to do, but he somehow wanted you to be aware of the extend of his power. You were at the same time scared, and irritated by the arrogance in his cold and taunting voice.

"I knew it's wouldn't be safe to open the Chamber again when I was still at school, so I decided to leave behind a diary, preserving my sixteen years old self in these pages, so that one day, I would be able to lead another, to finish Salazar Slytherin's noble work..."

He pauses, his smirk devilish and taunting.

"Haven't I told you ? Killing mudbloods doesn't matter to me anymore... For many months now, my new target has been you.