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| Series | Sonic Boom (TV series, 2014–2017) |
| Season | Season 2, episode 50 (S02E50) |
| Episode no. | 102 of 104 |
| US premiere | 4 November 2017 · Boomerang |
| France | 4 October 2017 · Retour à la vallée des Cubot |
| Written by | Ken Pontac & Warren Graff |
| Storyboard | Gael Leroux & Milena Mardos |
| Directed by | Natalys Raut-Sieuzac |
| Previous | Eggman Family Vacation (S02E49) |
| Next | Eggman: The Video Game – Part 1 (S02E51) |
Return to Beyond the Valley of the Cubots is episode 50 of Season 2 of Sonic Boom, the CGI comedy series made by Technicolor Animation Productions with Sega of America. It premiered in the United States on 4 November 2017 on Boomerang.
Synopsis

Tails’ little lab assistant D-Fekt can’t talk, which makes even a shopping trip a disaster, so Tails installs a voice chip. Able to speak at last, D-Fekt wants a life with meaning, but stints at the ice-cream stand and Knuckles’ gym go wrong thanks to his telekinetic powers, and his stand-up debut is wrecked by Eggman’s heckling.
Amy points out that Eggman treats all his rejects that way, which leads D-Fekt to the Cubot prototypes, who have lacked a guardian since FriendBot moved to the clouds. D-Fekt falls for Cutebot, takes the job and decides the best defence is attack. Next day he has conquered Eggman’s lair and turned the doctor into his servant, and Team Sonic thinks Eggman had it coming.
But when Sonic remarks that revenge is sweet, D-Fekt goes after everyone who ever wronged him, and the heroes have to fight him. Eggman escapes, borrows telekinesis from a D-Fekt prototype for a helmet and MeBot, and threatens Cutebot when the duel stalls. Sonic’s rescue gives D-Fekt the opening to rip MeBot to bits, and he departs with his Cubots and a warning: anyone who threatens them will answer to him. Hero or villain? Knuckles can’t decide.

Trivia
- D-Fekt comes from the 3DS game Sonic Boom: Fire & Ice, and this episode was written by Ken Pontac and Warren Graff, the writers of Rise of Lyric and Fire & Ice. It is a sequel to Season 1’s “Beyond the Valley of the Cubots”.
- On DVD in the US: NCircle’s Season Two, Volume Two (September 2021), Robot Uprising! (2020), The Complete Season 2 (2021) and The Complete Series Blu-ray (2022).
- French title: Retour à la vallée des Cubot. The episode aired in France on 4 October 2017, before its US premiere.
Watch the Episode
NCircle Entertainment, the show’s US home-video label, has not uploaded this episode on its own to YouTube at the time of writing, though its official channel carries two-episode compilations and Season 2 marathons. Season 2 is on DVD from NCircle (The Complete Season 2, 2021) and has been on Hulu and Netflix; see the series page for details.
Part of our Sonic Boom Season 2 guide. See the series page for the cast, the redesigns, the games and the comics.
Sources: air dates, writers and storyboard artists from Luke’s original Sonic Scene episode list, cross-checked with Wikipedia, Sonic Retro (Wayback copy) and Sonic Wiki Zone; synopsis written for Sonic Scene from the episode summaries on those sites; title card and screenshots via Sonic Wiki Zone, copied to our media library.

