"[S4E17] You Don't Know Jack " is the 17th episode of the fourth and final season of the Disney XD series , which originally aired on March 11, 2015. This episode is notable for being a Jerry-centric story that explores an alternate reality of the Seaford gang. Episode Summary

Olivia Holt returned as a guest star for this episode (and several others in Season 4) after having left the main cast to pursue other projects.

The episode features the main series regulars and several recurring guest stars who return for the alternate-reality sequences. Role in Episode Leo Howard

The vision includes a humorous (and possibly non-canonical) detail that Sensei Ty has 17 toes.

The main character who seeks his black belt and experiences the alternate reality. Dylan Riley Snyder Jack's loyal friend who assists at the dojo. Rudy Gillespie Jason Earles The dojo's sensei who struggles in the alternate timeline. Kim Crawford Olivia Holt

The plot focuses on Jerry Martinez, who is frustrated when Jack Brewer suspends him from taking his black belt test after Jerry throws an unauthorized party at the dojo. Following a blow to the head, Jerry experiences a vision of an alternate universe where Jack never joined the Bobby Wasabi Martial Arts Academy. In this reality: