Improv Everywhere, the flash mobbers famous for dropping trou on the subway (and then punking people to believe they rode it full monty), just released a new mission, and this time everyone is fully clothed -- in Ghostbusters uniforms!

The mission went down in the New York Public Library, recalling the opening scene of the classic '80s sci-fi/comedy.

There are also ghosts (sorry, no Slimer), proton packs and, of course, jaded New Yorkers who barely look up from their books.

Keep reading to watch the video of the faux Ghostbusters bust some ectoplasmic entities.