The Breach was a story arc occurring on the 15th of February, 2017, in which an extradimensional entity known as Zhdun invaded the Sandsverse, having arrived 17 days earlier than expected, and proceeded to wreak havoc. Seymour and Elmer were replaced by impostors, Horace went into lockdown, and the Brood was assailed by Wards. The Frog was nowhere to be seen during the event, and is speculated to have been asleep during the entire thing. Many non canon vendors were also affected by the Breach in various ways.
The arc began with Seymour's doppelgänger speaking in perfectly grammatically accurate English, causing immediate suspicion.  Elmer's substitute, a snub-nosed monkey, appeared shortly afterward. 
It ended when Horace appeared to sacrifice himself in order to free Seymour and Elmer, allowing them to prepare a counterattack. Elmer seemingly proceeded to reset the timeline. 
After the arc's conclusion, all related posts were deleted from the main vendor's blogs. The events of the Breach are chronicled here, with the exception of the Brood's posts.
- ↑ https://breachdetected.tumblr.com/post/157301024141/boarofthenorth100-zhdun-came-through-came-too
- ↑ https://breachdetected.tumblr.com/post/157296636916/seym-how-do-tapirs-celebrate-the-life-of-saint
- ↑ https://breachdetected.tumblr.com/post/157296773556
- ↑ https://breachdetected.tumblr.com/post/157296631406/sandsvendor100-more-notes-than-you
- ↑ https://breachdetected.tumblr.com/post/157296713611/someone-is-trying-to-replace-seymour
- ↑ https://breachdetected.tumblr.com/post/157302618526/fruitsoftheape100-elmer-wakes-violently-with-a