Author Timothy Zahn’s 2018 novel “Thrawn: Alliances” holds the answer to how the military strategist not only met both Anakin Skywalker and Darth Vader, but also how he figured out these two were the same person. Zahn, who created Thrawn in the “Heir to the Empire” trilogy of novels from the old Expanded Universe from the ’90s, returned to pen a trilogy of novels centered on the character beginning in 2017. “Alliances” was the second novel, telling simultaneous stories centered on Thrawn. One was set during The Clone Wars on a mission where he worked with Anakin, while the other was set between “Star Wars Rebels” seasons 3 and 4, with Thrawn working alongside Darth Vader.

Thrawn tends to like to play things close to the chest until the moment is right, so it’s never explicitly said in a “Eureka!” kind of moment that Thrawn deduced who Vader actually was. But “Alliances” makes it crystal clear that he knew. For example, Thrawn’s alien race, the Chiss, call their astronavigator children Skywalkers. Vader’s reaction to this little tidbit is what helped tip Thrawn off.

The key thing is that this means Thrawn not only knows who Ahoska’s master was, but he also knows what her master became. That may undoubtedly come into play as things continue to unfold here in the show’s season finale and beyond. Let’s not forget that writer/producer/director Dave Filoni is making a live-action “Star Wars” movie as well. Very few people knew who Vader was before becoming Palpatine’s right-hand man. What might Thrawn do with such information in facing Anakin’s former apprentice? One can only imagine… for now.

The “Ahsoka” season 1 finale airs Tuesday, October 3 on Disney+ at 9pm ET/6pm PT