Burnham and Book chase the couriers through a wormhole to a mirror-universe ship and a tense standoff over a hidden map piece.
Moll and L'ak flee into an unstable wormhole, and Burnham and Book follow in a shuttle. Inside they find the couriers' wrecked ship beside the ISS Enterprise, the mirror universe's version of the Enterprise, brought over by refugees escaping the Terran Empire. One of them later joined the 24th-century scientists and hid a map piece aboard, which Burnham recovers.
Book appeals to Moll through her father, but she resents him for abandoning her. L'ak reveals that the Breen have placed a death bounty, an erigah, on him for betraying them to be with Moll, and the pair hope to sell the technology to start a new life. Burnham and Book fly the Enterprise out of the wormhole with help from Discovery, and Moll and L'ak escape in a pod. Jen McGowan directed.