In Star Trek Discovery Season 3, Episode 13, time is running out for Culber and Saru on the KSF Khi'eth as more radiation is getting in and making them sick while they try to connect with Su'Kal. Adira arrives with radiation medicine to buy them some time. Surprisingly, the Khi'eth's holo program recognizes Gray and Culber and Saru are able to see him and talk to him. Together, they need to find an exit and contact Discovery within a few hours.
At Federation HQ, Vance launches an attack on the Viridian and the Discovery. Even at the risk of the Spore Drive, Vance says if Osyraa reaches the worlds they've lost first, the Federation is done for. Meanwhile, Osyraa is setting a course for Base 755, and is planning to use the truth serum on Book to get the coordinates for the Dilithium planet. Tilly and the bridge crew fight their way through the lower decks with the help of the Sphere Data-loaded DOT-23 robots. Burnham has been captured as well, and must find a way to break free and help Book and her friends.