Much a mystery still surrounds Thief 4. The game was announced in May 2009, and went silent immediately after. In February last year, images from Eidos Montreal’s website supposedly showed a first look at the sequel. Development began to ramp up in April last year after work on Deus Ex: Human Revolution was complete. In November, a set of storyboards appeared online, and in February this year, resumes revealed Square Enix to be sitting on a completed trailer for the game.

Internet sleuth Superannuation recently dug up new details on the title. Many of its developers, such as its lead level designer, two concept artists, senior animator, and other staffers, have left Eidos Montreal for studios such as Ubiosft or Warner Bros. Fabien Morisson, a current level designer, mentions having created the “last level of the game” in his LinkedIn profile, which, despite the multiple departures, could suggest that the game is coming together quite nicely.

Jumping back to that Thief 4 trailer – the demo reel for lighting and compositing artist Eric Wong earlier today included the first 30 seconds of the unreleased clip. He has since replaced it, removing the Thief 4 footage, but not before we were able to grab it. Watch it below.

Our upload was removed. The above upload is courtesy of YouTube user OdysseusVA. In case it’s taken down again, download the FLV here.