Hi, for a couple of days the game has driven me nuts. (I am on chapter six, "the Electric Buzz-Saw") I get to the collegue's office and no silver key near the sink. I can't find it anywhere! Where is it??

Once you have defeated the wheelchair machine-gunner, exit at the door opposite the one you entered. Move along the corridor to the office. The key should be right on the basin in the bathroom.