[And there's the million dollar question, isn't it? She stops, almost abruptly, and turns her head back towards them, her glasses catching the light as her eyes disappear behind the glint.]

Well, the Determination Experiments, o-of course.

[Without missing a beat, she turns to face them directly, and all pretenses are dropped; her features are replaced only with a cruel, unyeilding smile.]

I took the souls from Asgore and extracted Determination from all of them... and put them into monsters. I was testing to see if monster souls could p-persist after death... but as it turns out, Determination needs physicality to work! And monsters, well, they aren't all t-that physical.

So... they melted together. All of them, into new beings. New creatures. Screaming as their bodies fused together and t-they lost themselves.

[She's advancing on them now. Backing them into a corner. All the while, still smiling.]

And you know what? I never told anyone. I locked them in a basement and l-left them to die.