He asks him, later. As Alice looks around what is left of this proud empire, he corners the knight, more interested than offended.
"You called me a vessel. What did you mean, exactly?" The knight eyes him for a moment, a strange look in his eye.
"Vassal," he proclaims, as if reciting definition from memory. "A person who swears their allegiance to a higher authority in exchange for protection or land. In your case, however," and here he shoots him that look again, "I doubt your interests are protection or land in the.. conventional sense." A sniff of disdain, and Hatter realises just what kind of 'land' Alice is in possession of.
"Oh, woah woah woah, hey there!" He holds his hands up defensively. "Nothin' like that, Charlie-boy, I swear!" Another sniff from the knight. "I'm just.. here to see the lady safe and back on her merry way to her world."
"And you demand.. no reward at all?"
"Well.." And here he stops and thinks, really thinks, about leaving Wonderland. In the echoes of this place, the embodiment of what was once great and good in their world, he feels the anguish of one hundred and fifty years of wrongness and suddenly wants to cry. Which is pitiful enough. The words become true the minute he speaks them, as a lifetime of serving both sides crumbles beneath the weight of this revelation. "I just.. want a way to win."