During a quiet moment, Petra reveals to Eren that Levi wasn't always a model soldier; he was once a notorious criminal in the Capital's underground until Commander Erwin Smith recruited him. Hange’s Titan Experiments
Eren is moved to an abandoned, remote castle that serves as the headquarters for the Special Operations Squad (Levi Squad). Shingeki no Kyojin Episode 15
The second half of the episode focuses on Section Commander , whose eccentric obsession with Titans provides both humor and vital lore. During a quiet moment, Petra reveals to Eren