More details about Christa's mysterious past are expected to be revealed in the upcoming episode of "Attack on Titan" season 2.

The previous episode saw Christa and Ymir unexpectedly disappear while they were trying to save Daz during an intense snowstorm. Ymir thought the only way for him and Christa to survive was to leave Daz in the cold, but Christa insisted they could all make it out alive.

Ymir later confessed to Christa that she knew about her mysterious past. The former revealed that she knew Christa was a nobleman's illegitimate child — a plot point that will surely come into greater prominence as the series moves forward. In the previous episode's final moments, Christa revealed her true name, Historia, to a dismembered Ymir, who seemingly passed out immediately after.

A new sneak peek for the next episode has been released recently, and it centers on yet another pressing issue. The team from Stohess discovers that there has been no breach on Wall Rose. The Scout Regiment comes back to the Trost as doubts about the Titan attacks cloud their mind.

In addition, the teaser suggests that Eren will discover a shocking secret that will have a significant effect on everything. It remains to be seen whether this secret will change things for the better. If one thing is for sure, something bad is about to happen since Eren seems to be biting his hand. He intentionally hurts himself to shift into his Titan form, and what comes next is an explosive display of his transformation.

What does Christa's real identity mean to the show? How will the "secret" that Eren is about to uncover affect the story moving forward?

The second season of "Attack on Titan" airs every Saturday in different TV networks in Japan. Fans can also catch new episodes of the anime online via Hulu, Anime Lab, Crunchyroll, and FUNimation.