My plan is this: I'm going to draw a tiny figure down in the corner of the whiteboard. It'll be recognizably humanoid, but that's all of the detail that'll be clear. Depending on which coworker I target, the figure might go unnoticed at first. Over subsequent days, though, I'll sneak back into the office and change the figure, one small movement at a time, like a page-a-day calendar version of a flipbook.
I figure that the scene can unfold something like this: the figure turns its head and sees the world outside the whiteboard. It waves at first, then gestures with both arms. After a pause, it holds up an illegible sign. Then, dropping the sign, it begins to advance on the whiteboard, growing larger as it approaches. Perhaps another sign will be held up, not written in any recognizable language. The figure's features will start to become clear, and it will be obvious that it is nonhuman. This is partly because that'll be fun to draw, and partly because the odds of me drawing a human face well day after day are very low.
Eventually, the figure will reach the whiteboard and, raising a fist, begin to bang on it from the inside. Then I'll reach a decision point -- do I have it turn and walk away? Or do I fully commit to the project and break my coworker's whiteboard, allowing them to come back to the office after a bathroom break to discover shards of plastic on the floor and some sooty, dry-erase footprints leading away?
Let's be honest: it's probably the latter.
Mood of the Moment: amused
Auditory Hallucination: Theme from Sanctuary