Discovery investigates the subspace rift left behind by the DMA.
Tropes:
- A.I. Is a Crapshoot: Inverted. Zora is concerned that her newfound emotions mean that the crew can't trust her. For their part, the crew takes this development in stride. In the end, it's up to Zora to get the ship to safety when the crew (sans Burnham) has to take shelter in the pattern buffer.
- Both Sides Have a Point: Book thinks Discovery's time would be better served searching beyond Federation space for answers, because beings with the means and motive to create the DMA would not have escaped their notice so close to home. Burnham points out that the clues to who sent the DMA are local, so it's important to find the evidence first. Both turn out to be right when it's discovered that the DMA passed through the galactic barrier, putting its origin outside the Milky Way entirely.
- Continuity Nod:
- The anomaly contains particles from the galactic barrier, which appeared in several TOS episodes.
- The crew has to take refuge in the transporter pattern buffer so power can be diverted from life support. Zora notes that extended stays in the pattern buffer are possible but risky. Scotty, for example, survived decades in a modified transporter in TNG's "Relics", though the Red Shirt that he went in with wasn't so lucky.
- When Saru and Burnham discuss the mission, Saru makes references to similar missions carried out by Enterprise-D and Voyager.
- Know When to Fold 'Em: Burnham reluctantly orders a retreat when the void proves dangerous and their investigation is turning up literally nothing. It fails because there's no way to plot a course out and the spore drive can't be used, though this ends up providing a clue to the origin of the DMA.
- No Warping Zone: The void blocks access to the mycelial network, preventing use of the spore drive.
- The Reveal: The DMA is extra-galactic in origin.
- Soundtrack Dissonance: Zora sings "Stormy Weather
" to Burnham as they traverse the rift, the ship falling apart and the bridge in flames around her. - Space Is an Ocean: The solution to escape the void involves a process compared to sonar, sending a "ping" to a specific type of particle and then using that to follow it to the invisible rift.
- Thrown Out the Airlock: A Red Shirt engineer named Cortez gets sucked through a hull breach when he fails to make it past the containment field in time.
- Title Drop: The episode shares a title with the song that Zora sings for Burnham.
- Void Between the Worlds: There is literally nothing inside the subspace rift: nothing to scan, no turbulence, no background radiation, no matter of any kind. This makes navigation extremely troublesome, as there's no frame of reference for where the entrance is.
- The Walls Are Closing In: The void is slowly collapsing, threatening to vaporize Discovery if the edge makes contact.
- Written-In Absence: Linus is stuck spending the day under a heating lamp for an unspecified reason.
