Board Thread:General Discussion/@comment-31255465-20170923034221/@comment-33165688-20171007200239

Nangbaby wrote: I thought it was great self-contained story...but not a good series finale at all. Now I see definitely why Nickelodeon aired this episode before the other ones.

It is a purposely despressing arc, and the only way to reconcile the differences between the other episodes and this one is to treat it as an alternate universe. As others have mentioned, even though it seems like there is a point of divergence between the episodes we've seen and this bad future, there's little evidence that it's the case. The mutagen bomb is definitely technology from The Kraang, although that doesn't mean they launched it.

I don't think we're meant to look at the continuity that deeply, though. Instead this a Mad Max inspired universe that answers the question "What if the Turtles Fail?" and shows what could happen to these guys. Exploring it as a side-story is refreshing, but ending the series on this note would be terrible. Additionally, Nickelodeon has confirmed that it is non-canon with the main storyline, or a "tale of the beyond." Good enough for me.