Summary:

Ilya avoids skin contact with known sentinels as much as he can. It’s unlikely for compatibility to be high enough for a physical reaction. Ilya’s already managed to be a difficult guide. He can’t risk exposing his secret for the sake of camaraderie. But Hollander is pretty, and Ilya is not thinking about him being a sentinel, or the danger, or the pull he’s felt since he laid eyes on Hollander in person. He’s just thinking that he wants to touch him.

So he does.

And the touch sparks, bright and instant.

OR

Shane is a sentinel and Ilya is a guide. For the sake of their secrets, they should keep their distance. They don't.

It saves both their lives (and ruins them)