"We were like, ‘Can this be done?’" said creator Michael Schur of Thursday's episode, which was planned "to the millimeter" way in advance. “The first day of shooting, there was just a little panic about, ‘What if none of this makes sense?'” adds Josh Siegal, who co-wrote the episode with Dylan Morgan. Schur adds that preparation included "a ton of advance warning, and we finished the script really, really early, then we did a bunch of things along the way." ALSO: D'arcy Carden explains her midseason finale performance.