It was a very happy surprise.

At the curtain call for last night’s final Broadway performance of the beloved Avenue Q at the John Golden Theatre—where it enjoyed an amazing run of more than 2,500 performances—one of the musical’s lead producers, Kevin McCollum, stepped to the front of a stage crowded with cast members past and present, many of them puppets. And there, in a stunt worthy of the late David Merrick, and to the visible shock of nearly everyone around him, he broke the happy news: Avenue Q is moving back Off Broadway, and will reopen on October 9 at New World Stages on 50th Street. (You can buy tickets for the new run here.)

In an industry not exactly known for keeping secrets, the show’s producers and press agent, the sly-foxy Sam Rudy, had managed to keep Avenue Q’s move on the QT. “I had to talk to [director] Jason Moore, because he was staging the ending,” McCollum told me at the exuberant postshow party later that night at Del Posto. “The authors also knew; I needed their permission to do this. And that’s it.” Details of the move, he said, had only just been confirmed: “We kind of finalized it on Friday. In fact, today I went to the office to sign the paperwork. It was that late.”

The other welcome surprise of the night, for me, came in discovering just how well the show itself has held up. I am reluctant, as a general rule, to visit long-running shows after their first year; the energy has often evaporated, and the replacement casts are rarely as effective as the originals. Last night, obviously, was an atypical one for Avenue Q: Surely the audiences at regular performances have not screeched—screeched!—with excitement when the music started up. But the cast was remarkably good: not just original company member Ann Harada, making a delightful return to the role of Christmas Eve, but also Robert McClure and Anika Larsen in the lead roles originated by John Tartaglia and Stephanie D’Abruzzo. (Casting for the New World Stages version will depend on various people’s availability, McCollum told me, and should be set soon. “We needed to let everyone on Broadway have their closing,” he said. “But by tomorrow morning, we should have a list of people who might be interested. I’m sure some people will tell me at the party tonight.”)

As for Avenue Q itself: Robert Lopez, Jeff Marx and Jeff Whitty’s show remains a treasure—smart, funny, sharp, sweet and deeply felt. When it transferred from the Vineyard Theatre to the Golden back in 2003, many skeptics wondered if it could survive on Broadway. Well, that it certainly did. And now some of those same skeptics will wonder if it can make it Off Broadway. I think it can, and I hope it does. As McCollum put it last night: “As long as people are coming to New York to make their dreams come true and find their purpose, this show has to be a physical manifestation of that pursuit.” Jaded though it sometimes likes to seem, this city still needs its Q factor.