DSOGaming writes: "Valve's Marc Laidlaw has released a video teaser of something. In this video, Laidlaw questions himself whether he should 'do it'. This video shows off an elevator and Laidlaw's finger is almost touching the button for the third floor. However, towards the end of the video, Laidlaw pushes the 'L' button. By putting these two together, we may be witnessing the first official teaser for Left 4 Dead 3."