There's ten second of silence following Arya's demand. Jason's breathing is ragged, audible; his knuckles white on the table's edge-- not so much for the horror of what he sees as symptom of the internal battle with Etrigan, but Arya Stark has no way of knowing that.

tellll heeerrrr roars the fire. He resists. He has to pick his battles with Etrigan-- he cannot win them all, attempting to do so invites rude lessons from Etrigan in the futility of this-- but he is picking this one.

"Nothing," he grits out finally. "I see nothing."

It's a painfully obvious lie, but the fact that he manages to say it at all is his making a stand on a battlefield Arya Stark is not privy to.

Sadly, making a stand guarantees no victories. As Arya would know.