Not What He Seems

Plot

Dipper and Mabel Pines are spending their summer in Gravity Falls while their great uncle Stan works on an unknown machine in his basement under the Mystery Shack. In the secret laboratory, Stan rigs drums of chemical waste to power a portal machine and sets a timer for its full opening, causing gravity anomalies throughout Gravity Falls. The next day, law enforcement officers Agent Powers and Agent Trigger arrest Stan for stealing chemical waste.

The twins are taken to be remanded to Child Protective Services but escape after causing Agent Trigger to crash his car. They retrieve security footage from the shack, which shows Stan committing the crime. Dipper finds a box with fake IDs bearing Stan's face and newspaper clippings detailing Stan's death in a car crash decades prior, leading the twins to worry Stan is an imposter. Mabel finds a password on a slip of paper, identified as a button combination for the shack's vending machine.

In an interrogation room, Stan calls Soos, warning him of danger and ordering him to guard the vending machine. Stan escapes using a gravitational anomaly. Dipper and Mabel go to the vending machine, fight Soos, but Dipper inputs the password, revealing the entrance to Stan's lab. The twins discover Stan possesses two missing journals; Dipper puts them together with his own to form blueprints for Stan's machine. Under a black light, a secret message warns that activating the machine could tear apart the entire universe.

Production and themes

"Not What He Seems" was written by Alex Hirsch, Matthew Chapman, Jeff Rowe, Shion Takeuchi, and Josh Weinstein, and directed by Stephen Sandoval. The final sequence revealing Ford was animated in-house by storyboard artist Dana Terrace, with Matt Braly providing key animation. The episode halves the second season and ends with a cliffhanger, written to fit a hiatus and allow the writers to produce the episode sooner. According to Hirsch, half the fandom had guessed Stan had a brother—revealed as the author of the three journals—before the episode aired, with fans creating detailed exposés using PowerPoint presentations, flow charts, and timelines, rare for a Disney Channel show.

Hirsch had the character in his pitch to the network, and the writers placed clues from the first episode. The writers considered this element a risk, but found it necessary to keep characters interesting and break the status quo. Hirsch stated that Mabel would be forgiving of Stan, while Dipper would be unforgiving of both Stan and himself for the rest of the season, describing Stan being a con as a huge blow to Dipper's ego and a betrayal that would leave him feeling isolated from his family.

The episode guest stars Nick Offerman as Agent Powers, a character Hirsch described as a plot device to divide the protagonists and have them face their allegiances.

Broadcast and reception

The episode "Not What He Seems" drew 2.06 million viewers on its original broadcast, with an additional 1.02 million watching online, setting a record for any Disney XD series. Critics praised it highly; Alasdair Wilkins of The A.V. Club called it an "instant classic," noting how the narrative was built around the relationships between Dipper, Mabel, and Stan, and lauding its character work, comedy, and art style. Vrai Kaiser of The Mary Sue named it the series' best episode, highlighting its use of color contrasts to shape the tone and how it upended viewers' "assumptions of safety." Storyboard artist Alonso Ramirez Ramos earned an Emmy nomination for his work. The episode also received two Annie Award nominations, for Best Animated Television/Broadcast Production for Children and for Writing in an Animated Television/Broadcast Production.