Right, though we'd have a little fun. This is a nice little game that some of you may know about, and if you do please don't spoil the fun for those new at it! Basically, people who know about the game will tell you what can be found beyond the green glass door. The aim of the game (is it a game? More of a puzzle) is to work out what can be found beyond the door and what cannot. Once you've cracked it, join in with saying what can and can't be found (but obviously don't reveal the secret). An example: Beyond the green glass door there's a moon but there is no sun.