Marvel's 'Agents of S.H.I.E.L.D.' has been a bit less transparent in promoting a new season than that of its DC counterparts, but that hasn't stopped the ABC drama from getting viewers in on the game of its latest mystery. We know why Coulson lives, but what's going on in Phil's noodle to be scrawling alien equations all over a Hollywood billboard for 'Agents of S.H.I.E.L.D.' season 2?

As appeared over LA in keeping with last year's minimalist display, the newest 'Agents of S.H.I.E.L.D.' season 2 promotion finds a billboard adorned with the same alien equation scrawled on a wall by Agent Coulson (Clark Gregg) in season 1 finale "Beginning of the End." Naturally, whatever Kree alien blood saved Coulson's life also put some funny pictures in his noggin, but what it means for the Director of our new S.H.I.E.L.D. in season 2 is anyone's guess.

Elsewhere of 'Agents of S.H.I.E.L.D.' season 2, we know that that 'Xena' star Lucy Lawless will play veteran S.H.I.E.L.D. agent Isabel Hartley, while Nick Blood will join as mercenary and comic STRIKE character Lance Hart. ‘Dollhouse’ star and Whedon favorite Reed Diamond will play Daniel Whitehall (Secret Wars’ Kraken) as a Hydra baddie, while 'Twin Peaks' Kyle MacLachlan will appear as Skye's apparently-gooey father. Still uncast is the role of comic superhero Mockingbird, also known as Barbara "Bobbi" Morse, though we do know Adrian Pasdar's Glenn Talbot will return to menace the team.

We're no expert in alien equations, but might the success of 'Guardians of the Galaxy' mean a bit more alien activity filters down to Earth this season? Might the funny pictures in Coulson's head bring the Kree to earth? Tell us in the comments what you want to see when Marvel's 'Agents of S.H.I.E.L.D.' returns for season 2 on September 23!

Oh and hey, need to catch up on the first season with only 60 seconds to spare? We've got you covered!