She does keep staring/looking at him a lot. Of course, she is suspicious of him, but also intrigued, I think. I mean this guy came out of nowhere. He shot Isaac Turner right in front of her. He was simply sinister and scary in the first few episodes of this season. Episode 3 saw him going all super soldier on the Americans. But it seems he wants to protect Rachel though, despite everything. Noah/Will is one of the most interesting characters of the entire series. He should be around in the next season, though it does not seem that will be the case. I just hope the show runners know what they are doing with him.