[ Her eyes follow him as he paces, A method to grant him a way to prevent others from summoning is not enough of payment alone, it seems. Freedom’s price comes with questions.

Moreover, he’s by far established he is perceptive, shrewd. Any explanation or defense at this point would be giving him extra information, more pieces he can put together.
Either she risks that, or she stops here. ]

I… need to make something. [ Clearly, something this world doesn’t have. Similar to the spell she’s offering him, it’s fair to assume whatever she wishes to try won’t work, either. ] To protect others… and to survive.

[ But shrewd men aren’t moved by the kindness of their hearts. Rem bites on her bottom lip, fighting back a feeling of loss. ]

I’m offering you summoning autonomy. Is that not enough?