You are walking around the Black Mesa facility, and you run into a door that has been shut. Using a keycard, you open it, and find an unsuspecting scientist. He jumps up in the air as you open the door, yelping in fear.

Oh, dear!

He calms down when he sees that it's just you, and takes a deep breath. He then speaks with a slightly shaky voice.

Oh... Gordon, you scared me there...