TF2 fans have uncovered a pile of clues with that distinctive Valve ARG flavour, suggesting a third faction is on the way to the class-based multiplayer shooter.
The most obvious come directly from Valve; if you visit the Team Fortress website and click the bloodstains on the free-to-play banner, you'll be taken to a mini-site with the URL "gray" which hosts a mysterious note.
Although nothing has been confirmed, knowledgable fans have linked the teases with the upcoming Man vs Machine update, which has been teased repeatedly for two years now, and is expected to include playable robots. A Kotaku reader explained some of the origins of the ARG for those of us who don't spend hours deconstructing Valve's moderately mental marketing:
"Someone found out by equipping an item that was not supposed to be equippable and high fiving someone, the person you high fived would receive a secret message in the form of a joke. The jokes turned out to be hidden hex code, which then revealed nine things. Eight of them just revealed a word, but the ninth one revealed a zip with a password lock (a Keepass thing). Using the words as a PDP code list somethignsomthingsomething (I'm not exactly sure here), people found a link inside linking to [tf2.com] which turned out to be a crafting recipe in game. Crafting all the items together caused a GAME wide message, linking the comic."
Right, Seems straight forward enough. Here's a pretty awesome fan video collecting together evidence found so far.
Thanks, Blue's News - and Sadismek.