Christopher Nolan’s Inception – his mystery-cloaked follow-up to The Dark Knight – has only been shooting for a short while, but already a teaser trailer has made its debut online, over at Yahoo! And it’s damned intriguing…

It starts off with the now traditional Warner Bros. shield before a quick zoom in reveals that it’s made of buildings. The first shot – a spinning silver top. The second – an actual cityscape (Tokyo, one of the cities where Nolan is shooting the film, along with London, LA, and Paris). The third – the movie’s star, Leonardo DiCaprio, looking mean and moody with his now-customary goatee, looking at something… which could be the fourth shot, of a guy (who looks a lot like William Fichtner) being dragged away, against his will, by two guys on a rooftop.

The fifth shot is where this really gets weird. All we knew about Inception previously was that it was “a thriller that took place in the architecture of the mind”, which seems to be Nolan code for “some really freaky shit is about to go down.” So, in quick succession, we get a glass of water, where the water is tilting sideways, followed by an evocative tagline: “Your mind is the scene of the crime”. And then the money shots as DiCaprio squares off against a guy dressed as a porter in a hotel corridor – except the angles of the corridor keep changing, so one minute they’re fighting on the floor, then the walls, then the ceiling.

It’s pretty damned impressive, and slightly reminiscent of The Matrix in its trippy, free-floating, gravity-defying style, and it’s not at all what we were expecting. I still haven’t the foggiest about what’s actually going on here, but there’s no doubt that it’s going to be cool. Very cool.

In fact, with Nolan on board as the driving force, an estimated budget of $200 million, and a cast that also includes Cillian Murphy, Ellen Page, Joseph Gordon-Levitt, Marion Cotillard, Ken Watanabe, Tom Hardy and Sir Michael Caine, Inception could be the dark horse of summer 2010.

But don’t take our word for it – zip over to Yahoo! Movies and take a looksee yourself.