Discovery follows the clues in the diary while Book investigates Moll and L'ak. Book makes contact with them and discovers something that challenges his willingness to oppose them. Saru, having decided to retire from Starfleet to pursue his romance with T'Rina, spends his last day on active duty.
Tropes:
- Ascended Meme: An endearing nickname for Saru, especially when he gets into action events, was "Action Saru". This episode canonizes this and reveals that he knows that he's been called that and loves it.
- Call-Back:
- Burnham and Saru discuss various 24th century Romulan cultural traits first established in the first season of Star Trek: Picard.
- Saru reminds Burnham of the day she first boarded Discovery (to his disapproval) and the day he passed through vahar'ai. He also reminds her not to touch the swamp kelp.
- Central Theme: Second chances. Burnham remains in debt to Saru because he gave her a second chance. Meanwhile, Captain Rayner is Hauled Before A Senate Subcommittee for his impulsive actions in the previous episode, and Vance forces him into an early retirement to make his superiors happy. Burnham, with Vance's blessing, brings him on as her Number One to succeed Saru.
- Commander Contrarian: Rayner warns Burnham that, as her Number Two, he won't be a Yes-Man. Burnham replies that she picked him for precisely that reason, as Saru advised her to.
- Connected All Along: Book realizes that "Moll" is actually Malinne, the daughter of his mentor, Cleveland Booker IV.
- Continuity Nod: The installation on Lyrek was originally built by the Promellians.
- Destroy the Evidence: Moll and L'ak used their weapons to destroy the writing on the obelisk after getting the clue. Fortunately, some organisms nested in the recesses where the writing was, allowing Saru and Burnham to illuminate the clue, revealing that Moll and L'ak actually missed an important part of it.
- Digging Yourself Deeper: Rayner tries to justify his actions by claiming that war is always around the corner, warning that the Breen are fighting for a new leader and the Orions are rearming themselves, accusing the Federation of being blind to those potential threats. He gets into an argument with Vance over this, forcing Rillak to call for a break. Rayner realizes he screwed up when he utters a quiet "Shit..."
- Dismantled MacGuffin: Hidden in the ruins is one of five pieces of a Progenitor map, which fits into the symbol depicted in the diary.
- Durable Deathtrap: The Promellian ruins still have an active security system powered by the planet's electromagnetic field.
- EMP: Since the security system is powered by the planet's electromagnetic field, Tilly tells Burnham to overload her phasers to produce an electromagnetic burst, thereby disabling the system for a while.
- Hauled Before A Senate Subcommittee: Burnham and Rayner are brought before Vance and President Rillak over the mission from the previous episode, since they lost Moll and L'ak and their actions led to an avalanche that nearly wiped out a trading outpost when the Federation doesn't need that kind of bad publicity. Burnham's in the clear, since she objected to Rayner's actions which ultimately led to the avalanche, but Rayner isn't so lucky thanks to a combination of an unapologetic attitude and an unprofessional outburst.
- Honor Before Reason: Rather than destroy or remove the obelisk so that Moll and L'ak won't be able to find the final verse of the clue when they return, Burnham orders that, out of respect to the dead, it should be restored to its original condition.
- Man Hug: Hugh and Book share a hug when they see each other on Discovery.
- Mission Control: When Tilly and Adira get stuck trying to work out what the drones' power source is, Rayner calls in to assist, having been monitoring their situation. Rather than answer their questions (he's not a science guy), he uses his experience to guide them through figuring it out with their own expertise.
- More Expendable Than You: Saru and Burnham briefly argue over who gets to draw off the drones and risk getting shot in the back. Burnham wants to be the distraction, mainly because she does not want to get Saru killed right before his wedding, but Saru successfully argues that his superhuman abilities make him more suited to the task, and that T'Rina more than anyone would not want him to allow his personal life to affect his duties. It's a close call, but he comes away with just an easily healed shoulder burn.
- Non-Answer: When asked if she agreed with Rayner's actions, Burnham initially hedges by questioning what relevance her opinion has and pointing out that Rayner didn't directly cause the avalanche, until Rayner tells her he's okay with her saying what she really thinks.
- Oh, Crap!: While talking to Moll and L'ak, Book introduces himself as "Cleveland Booker", causing Moll to freak and cut the connection. This is what sets Book off to figure out who she is.
- Pun: Saru comments that missing his wedding because he got himself killed would be a grave disappointment.
- Red Herring: The clue on the obelisk makes reference to "opaline waters", seemingly referring to Betazed. Burnham and Saru realize, however, that a paranoid Romulan would leave a false clue for potential thieves and they have to think like a Romulan, meaning the clue is incomplete and the rest is hidden nearby.
- Reluctant Retiree: Because of Rayner's actions on Q'mau and his outburst in front of Vance and Rillak, Vance forces Rayner into an early retirement so he can save face. However, Burnham puts him on Mandatory Unretirement, recruiting him as her newest Number One to succeed Saru.
- Retirony: Subverted. Saru's retirement is an overarching theme, and the episode wastes no time in putting him in a position where he has to distract the enemy while Burnham does some sabotage, with Burnham quite aware of the risk she'd be putting him in days before his wedding. Despite this, he survives.
- When the Planets Align: The first clue is hidden under an obelisk that is directly under the shadow cast by an eclipse of the planet's twin moons once every seven years.
