That's all she needs to hear.

Luce doesn't bother to hold back. Daringly, she scrambles up onto the stage and makes a grab for Sans. To the Doctor, she tries to give the impression of connecting to everyone before she calls out mentally-

We have to leave NOW!

Sans, obviously, is the one who can do this easiest, and she already knows who to get him to. She can only hope, however, that Stella and Arpegius protect them while she tries to get Sans up, murmuring reassuring nonsense in Italian to the skeleton.