Peridot's desperate motions trigger a reaction in Sans's mind, at first based hazily in the idea that he's supposed to be defending the Prince and his interests. She looks angry, ready to attack, to interfere, and the Prince is right there... but when he tries to pull himself up to intervene, he can't.

It sets his mind spinning. She's yelling at the Prince to let them go and he's trying to understand why. He's fighting against her now, he nearly killed Lambert, he... why?

Why is he doing this? He's desperately trying to rationalize how it came to this, but in this fog of utter exhaustion he can't figure anything out. Why did he come out here, what is he doing, why were they fighting, what is happening to him...?

In a surge of confusion and anxiety he feels the desperate need to beg for help before all of this slips away again, but he can't seem to speak, can't find the words. He just sees Peridot looking ready to attack the Prince and desperately wants her not to.

"Peridot..."

Lambert and Peridot shouldn't be out here. Words balance behind his teeth, but nothing comes out. All he can do is vaguely raise his hand before the arms of mud reach up and cling to his shoulders and throat, starting to drag him down. He can't help but struggle, as futile as he knows it is. He's too terrified to do anything else.