"I was asked to come and help perform a jailbreak."

A rescue mission, then. Curious. 

Jax was tempted to ask her why he should trust her, but knew that was pointless; having no prior experience of her trustworthiness, or anything about her at all, she could say he should trust her for any reason she could come up with, real or invented, and he would be just as in the dark as if he hadn't asked the question. She was obviously adept enough at breaking into the palace grounds, he figured he could trust her to be able to get them out, hopefully without hurting any of the palace guards or, heaven forbid, his own men.

The only thing left to consider was whether or not he wanted to be taken from his captivity. Discomfiting as it was to be in prison on a false charge, and even though his life hung in the balance, his duty was to the Queen - and even though she was dead, his duty was still bound to her wishes. She deserved to have her murderer found and punished, the people of the kingdom deserved the same, and if he was broken out of prison, he could no longer communicate to the Guard what he discovered. But he was so limited in his investigation while he was in this cell, and of course, if he were put to death before he could convince them he didn't murder Ismari, well then, however far his mind got him in its investigation of the murder would be worthless. That made his decision for him.

Jax regarded Celinny with a hard focus. "I'll allow this on one condition" he told her. "Once I am free, you will either aid me, or not stand in my way, in my attempts to discover what truly befell Queen Ismari. I don't know why you're getting me out, but even if the Queen is dead, my duty to her is not. My life will be dedicated to finding her murderer and stopping their plan from moving forward." Then he looked down and added, almost to himself, "surely their intent was not merely to kill a queen."

Looking at Celinny through thick steel bars, suddenly his disposition altered. Jax raised an eyebrow and said with a grin, "now I'm very curious to know how you plan on getting me out of here."