Had?

At this point, Susan wasn't sure what was making her heart race so much as she approached the hallway of Harold's chamber while looking all around to make sure no one was paying attention to her.

Was it because she was scared? Apprehensive? Or perhaps it was because she wasn't sure what to expect from meeting Alvin? 

However, when she got closer, the first thing she noticed was that things were different this time. Three guards were standing right outside the door. And judging from their dress, she knew they were high-ranking guards who worked only for the king. Even their appearance looked scary. 

She had a feeling that Alvin was still inside, so she approached the door despite their presence and was met with 3 pairs of vicious eyes staring right at her.

None of them moved out of her way and just stood there, watching her as she approached.