Island Tarle was very sure she was ready to die. And she is certainly in the right place to make that happen.
In the hands of her enemies, Isla isn't even sure Gray is alive, or if she can discover what she was sent in to learn. With her memories of a battle long lost beginning to make sense, she is more interested in learning what she can do, rather than the mission. Or perhaps the two are intertwined.
Gray's only hope is that Isla is alive somewhere. But he has no way to get to her and even if he did, he has no idea what they do next.
The Rohen is far more complex than either of them understood. They may have to learn to work with those they don't trust to find a way to save their universe.