The Simpsons has told countless origin stories during its 699-episode run, but as you’ll learn from Sunday’s next milestone (Fox, 8/7c), the residents of Springfield still have a few untold surprises up their collective sleeve.
Episode No. 700, titled “Manger Things,” takes us a few years into the past — to a time before Maggie was born, when Homer still had (some) hair — for a revelatory Christmas tale. Per the official synopsis, longtime fans can expect to “learn a secret of Flanders’ past and discover a never-before-seen room in the Simpson home.”
The photo above offers a glimpse at the previously unseen room, but you’ll still have to tune in on Sunday to find out Flanders’ big secret.
The Christmas-set episode also invites us to a disastrous holiday party for employees of the nuclear power plant, which ends with Mr. Burns releasing the hounds on the festive crowd. TVLine has an exclusive sneak peek of that party foul below.
And don’t forget, the show will be hitting another mini milestone in a few years — Fox recently renewed The Simpsons for Seasons 33 and 34, ensuring that it will continue through at least 750 episodes.
Hit PLAY on the video below for a taste of what Episode 700 has to offer, then drop a comment with your thoughts on The Simpsons‘ latest milestone below.