Not every Improv Everywhere stunt is as happy-go-lucky as No Pants Subway Ride day.

This week’s latest trick organized by Charlie Todd sent between 40-50 improvisers into a Gap store on New York City’s Fifth Avenue, wearing Morphsuits and Gap-like clothing to masquerade as store mannequins. Everything went according to the usual plan — customers, employees and passersby slowly realize what’s happening, record their bemusement and move along — until a Gap employee called 911 and reported the group as a “flash mob.”

The NYPD arrived on scene and began handcuffing the human mannequin imposters, as well as Todd, who identified himself as the organizer. That’s Todd in plainclothes and blue Cubs cap on the lower right corner of the photo above, handcuffed on the floor.

“While that shocked us and seemed like a huge overreaction, I guess it makes sense if you think a robbery is happening,” Todd recounts in his mission debriefing online.  “The timing of all of this was terribly unlucky. The managers on the second floor had just started asking our participants to leave the store. Participants were taking the escalator down to the first floor and walking directly into handcuffs. Of our 40 performers, about 20 ended up in cuffs. The cops actually ran out of handcuffs. Some peformers were able to unzip their suit and tuck the head back in their shirts. They walked out the front door looking like anyone else. Two participants figured out what was going on and went to a Gap dressing room. They removed their suits entirely, stuffed them in their pockets, and were immediately transformed into a normal customer. I felt terrible as all of this was going on. 20 people who I didn’t even know personally were cuffed on the floor all because of me. I quickly went downstairs and claimed responsibility and identified myself as the organizer. “You’re the ORGANZIER???” a cop responded incredulously. I think maybe he still thought it was a robbery at that point? “OK well you’re getting cuffed too Mr. Mastermind.”

But Todd understood. The Gap employee had reported a flash mob, and the police think flash mob equals looters thanks to mainstream media and law enforcement reactions in other cities in recent years.

“I’m never happy when the police show up to an Improv Everywhere event. It’s been 8 years since the last time we had an incident like this at (a retail store Best Buy.) It’s never our goal to get the police involved, and I feel bad about wasting the NYPD’s time. I really thought the Gap would do one of two things: 1) Ask us to leave or 2) Do nothing and we’d leave on our own in 10 minutes. In recent years, Staples politely asked us to leave when we held a boardroom meeting in their store, Macy’s did nothing as we had a slow motion Matrix fight, and Starbucks did nothing as 20 men claimed to be Spartacus. You never know how a store is going to react to an unauthorized performance on their property. Thanks to the awesome group of participants who helped us pull this off. Everyone was great and handled themselves so well when things got tense.”

Here is the mission, encapsulated in video highlights (note: There’s a link to the Best Buy incident at the tail end of the video). Roll it!