Just when I thought I had stumped you guys again, a mysterious Twitter hero swooped in at the last minute and solved this week's Name That Data! But before I reveal the answer, let's take a walk through the Gallery of Wrong.

Hannah Neprash knew exactly what the data wasn't.

Jeff McCarthy was confident in his deductive powers.

Tucker Samuelson was on the right track.

The all-star team at PolicyMap was in the right universe, but they had the wrong dataset.

Now at this point I figured I had you guys - if PolicyMap couldn't get it, what hope did anyone else have? Then all of a sudden, on Saturday afternoon this tweet appeared.

Michel is, in fact correct - the map shows average daily air pollution, measured in micrograms of fine particulate matter per cubic meter, from 2003 to 2011. This is the nasty, superfine stuff that can easily make it through air filtration systems. A recent study showed that the pollutant can affect indoor worker productivity even at levels well below U.S. air quality standards. The data come from the CDC.

Now, the interesting thing about Michel, this week's winner, is that his correct guess is his only tweet, ever. It's akin to some mysterious stranger walking into Yankee Stadium in the bottom of the ninth, picking up the bat, and hitting a grand slam home run to win the game.

Michel is both the hero Name That Data deserves, and the one it needs right now. For this, I award him the title of Dark Knight of Data, and certify that he was Right on the Internet When So Many Others Were Wrong.