Given what Nathaniel said about making eyes vanish, Remington was afraid when the djinn raised his hands to try and heal the human. But Remington would be useless if he couldn't get his head right, and then he'd probably die as a result of being unable to fight to his potential. It was worth the risk. Thankfully, it paid off.
Seconds later, Remington felt a rush through his brain. He gasped from the strange sensation, but then he breathed easy. The pain was gone. The fog too. He could see normal. "It worked," he whispered to Nathaniel, in English, not wanting anyone else to understand their conversation. Of course, speaking a strange language got a lot of attention, but less than some magical healing would.
"Listen.. wherever they're taking us, you need to let me take as much of the punishment as possible, especially since it seems you can heal me. But only heal me if and when I say, alright? We have to be careful what they see you do. If they know about your powers, they might try to manipulate them. Djinn exist in this time period, and people are more likely to believe in magic as well." They might enslave Nathaniel and force him to do their bidding. "So we'll try to keep a low profile and stay as healthy as possible until you've rested and figured out how to get us home. Deal?"