To celebrate Ms. O's 100th anniversary, the agents go back in time to witness her last case as an agent. However, something goes wrong and they change the future for the worse.
| Actor | Role |
|---|---|
 Anna CathcartOlympia | Olympia |
 Isaac KragtenOtis | Otis |
 Millie DavisMs. O | Ms. O |
 Olivia PrestiOona | Oona |
 Christian DistefanoOwen | Owen |
| AAlexander FonsecaChuck Shmumbers | Chuck Shmumbers |
 Elena JuatcoHiccups Lady | Hiccups Lady |
| AAmy KhouOdena | Odena |
| JJoshua KilimnikOdd Todd | Odd Todd |
| PParker LauzonTrumpet Agent | Trumpet Agent |
| TTristan LyOsmand | Osmand |
| TTony SciaraGino Confalone | Gino Confalone |
 Chris RiverDramatic Kid Announcer (as Christopher River) | Dramatic Kid Announcer (as Christopher River) |
| TTate YapO'Donahue | O'Donahue |
| KKaitlyn YuPatternista / 80's Ms. O | Patternista / 80's Ms. O |
 Anand RajaramMr. Fonts | Mr. Fonts |
| SSean SullivanMan with Rain Problem | Man with Rain Problem |
| KKevin WhalenMan with Future Toast | Man with Future Toast |
 Christian Dal DossoOdd Todd Guard (uncredited) | Odd Todd Guard (uncredited) |