Since Wednesday, the Time and Temperature Building in downtown Portland has been flashing an unusual message and some Portland residents aren't quite sure why. Well here's the reason.

This weekend is the American third season premiere of 'Sherlock' on PBS. The show is produced in the UK by the BBC, and is shown here in the states several weeks later. 'Sherlock' is a modern day version of the famous detective and re-imagines several classic stories from author Sir Arthur Conan Doyle. It stars Benedict Cumberbatch (Star Trek Into Darkness) as the modern day Sherlock and Martin Freeman (The Hobbit) as his Watson.

If you haven't watched the show, I highly recommend it. You can find the first two season on Hulu and Netflix. In addition to the premiere on Sunday, there is a special advance showing tonight at the State Theater, which is probably why the sign is flashing over Portland.

Seriously though. Watch this show. The second season cliff hanger is brilliant, and I can't wait to see how they resolve this! There's so much more I could say, but no spoilers!