Interesting piece of "key art" -- fancy term for billboard -- that "Mad Men" released Monday and will appear on the side of a bus near you any minute.

The illustration is by British illustrator Brian Sanders and effortlessly captures a late '60s go-go era vibe -- apparently in chalk. But what's striking here of  course are the Two Dons -- each warily passing the other in the street. Meaning? Let the guessing game begin (will "Mad Men" turn into "The Patty Duke Show" perhaps next season?)

advertisement | advertise on newsday

There's the Light Don and the Dark Don; one Don is holding the hand of a woman; the other is clutching a briefcase, with police cars assembled in the background. The Yin Don. The Yang Don. That plane ascending in the background? Groovy, daddio! (as they used to say in the '60s -- or did they used to say that?) Why is a plane -- which apears to be an early late '60s version of a 727 (series 100; oh the things you learn on "Mad Men") -- flying over Central Park? Did they have an airport there back then?

New season begins April 7.