At the start, the Muppets realize their recent movie hasn't made them as hot as they'd hoped. An oily Hollywood type preys on their vulnerability and persuades them to hire him as their manager. Little do they know that the man who has identified himself as Dominic Badguy (Ricky Gervais) is really a scheming jewel thief. Dominic arranges a European tour for the Muppets and immediately dispatches Kermit; the other Muppets don’t know that their trustworthy frog leader has been replaced by prison-escapee Constantine, Dominic's partner in crime, who looks just like Kermit save for a Cindy Crawford mole on his upper lip. Meanwhile, Kermit is whisked off to the gulag, where prison mistress Nadya (Tina Fey, looking quite fetching in a fitted Russian officer's coat and matching fur hat) tries to have her way with him. Her PG-rated way, of course.
The story matters only in that it creates opportunities for heaps of ridiculousness, and writer-director James Bobin (who also directed The Muppets), along with co-writer Nicholas Stoller, mines them skillfully and breezily. You haven't lived until you've seen grizzled Siberian jailbirds, played by Jemaine Clement (Flight of the Conchords), Ray Liotta, and Danny Trejo, singing the living daylights out of Hamlisch and Kleban, and Fey slinks through several musical numbers with vixen-like ersatz Russian charm.