In 38 BCE after the assassination of Ptahmose, Kashta alongside Tahira and Mentor, Bayek, were ambushed in their bureau by Roman soldiers under the orders of Gaius Julius Rufio. The soldiers set fire to the building, resulting in the Hidden Ones fleeing the bureau and being captured. Kashta and Tahira were brought to Fort Clostra, where they were saved by Bayek and Amunet. After Tahira died from her wounds sustained during their capture, Kashta was furious and wanted revenge against Rufio, but he was told by Amunet to bury Tahira and to leave Rufio to her and Bayek.
After Rufio's assassination, Kashta and the rest of the Hidden Ones moved their bureau to a cave in the mountains behind Arsinoe. Later on, he was present when Amunet and Bayek laid down the first tenet of their creed: to never harm an innocent civilian.