Choosing a more subtle approach—but no less speedy—is the now invisible tiefling hot on her heels.

She'll have seen him coming around the corner prior to their arrival, giving barely a nod of acknowledgment before, with a gesture, his form had flickered into non-existence, and he allowed his boots to scuff against the floor to indicate to her he's following along. By the time they're closing in on the library—

Well, he's quiet. Borderline silent. He's already gotten a knife into hand, held close to himself, trailing swift and sure in Abby's wake and slinking into the library underneath the sound of her hey, aiming for a wider trajectory to get himself a good angle. Reflexively avoids a shaft of light so as not to disturb the drifting dust and give himself away.