For the first time, Strange is grateful for the curse. There is no way he could explain it in a way that Fitzjames could understand. It might be his father. It might not be. It might be Fitzjames or Crozier or Franklin—how odd, why would he think of a man he's never met. It matters and yet it doesn't. He needs the answer but he feels like he he can go along without it.

He wants to tell Fitzjames all that but if he opens his mouth then he will vomit up rotten tomatoes and the little metallic thing will sink further down his throat. So instead, Strange reaches over and attempts to tenderly lay a hand on Fitzjames's cheek as he gives the captain a gentle smile, hoping the gesture will substitute for the things he cannot say.

That is it but it isn't it but it is it. A Fitzjames that's not Fitzjames but is Fitzjames. He has no way to explain it, his mind is too full of the sky, so he offers what he can: comfort. Besides, the flowers are wilting. He is supposed to protect all the crew, and that includes this man here.