Cold concrete gave way to the bright steel of the elevator as he stepped over the threshold and into the box. Thankfully, it played no music. His appointment was on the fourth floor, at two o'clock. His watch read quarter to two. He had time, and he had never visited this facility before. The panel of smooth, round buttons lay before him invitingly, there were many, many levels to the Center for Planetary Innovation; some were labeled ominously and had no button; "Disjunction Level" in particular intrigued him, but alas, no button. Impatiently, the doors slid closed.
Towards the top of the panel he saw a button with a taped-over label. The tape read "NO SERVICE", but he worked the edge loose with his thumbnail and, to his delight, saw graven in the simple sans-serif elevator font the word "MOON". He pushed it. The little circle around it lit up blue, and he smiled.
He rocked up on his toes to see if he could sense any appreciable acceleration, but he could not. Gravity felt normal. He sighed, looking again at his watch. He had ten minutes now, so he ought to just report in on the fourth floor and make his presentation. It was not a very good presentation, merely a summary of his research activities over the past month, wherein he had found little of note concerning time-dependent albedo variations in the Mare Tranquillitatis. They were small, they were aperiodic, and the best he could say was that they might have to do with unexpected absorption and emission bands of particles entrained in the solar wind; this was as much as to say he had no idea. He pressed the button for the fourth floor.
Curiously, it blinked red, then went out. The button labeled "MOON" remained highlighted in blue. He blinked, and rocked on his toes again. Nothing much. He checked his watch, and tried the door-open button. Still nothing.
He was caught quite off-guard, then, when he slammed into the ceiling of the elevator five minutes later. He was less surprised, though still rattled, when he thudded back to the floor of the elevator, his bag splattering him with paper and pencils, and his lunch quite crushed by its brief stint as a shock absorber for his laptop. With a cheerful ding, the floor indicator said MOON and the door slid open.