In Season 4 it was revealed that in 2014 Jael and her sister (The Gorgon) decided to undertake a suicide mission in hopes of destroying Pandora's Box, Jael voiced her concern to her sister saying that nobody knew the way back from Purgatory. However Cassidy stated that Pandora's Box, is the source of all evil and her life was a small price, reluctantly Jael pulled out one of her daggers and stabbed her sister who was then transported to the Museum of the Dead by the power of two unknown artifacts but never returned. Sometime later Jael undertook a mission with fellow Society members Ryu and Calliope to travel to the town of Everlock on October 13,1978 to stop the Carnival Master.
Episode 1 - The Clowns Here Kill Part 1
Episode 7 - Funhouse
Matthew told the rest of the guests that he saw a blonde woman (Jael) and an Asian man (Ryu), and they had told him that he wasn't the first person to appear at the Church in the world between the Land of the Living and the Land of the Dead. This is a reference to The Clowns Here Kill Part 1, where Joey meets Jael and Ryu, proving his story to be true.
Episode 10 - The Carnival Master (Episode)
Ryu, Jael, and Calliope arrived a little too late to save Everlock, and had to lock it in time. While Calliope went to fend off the guardians, Ryu and Jael faced the Carnival Master. Ryu's neck was snapped, and Jael used the last of her life force to trap the Carnival Master when it was revealed that he had the life stones and could not be killed. Joey, Matt, and Nikita used the life stones and Harp of Lazarus to bring Ryu and Jael back to life so that they could defeat the Carnival Master once and for all. Jael is the one to finish the Carnival Master off.