Star Trek Discovery S4E9: “Rubicon” review and reactions

Star Trek Discovery ends a DMA but ramps up stakes in “Rubicon.”

In “Rubicon,” the latest episode of Star Trek Discovery, Burnham and crew are going after Book and Tarka, to prevent them from using Tarka’s isolytic weapon to destroy the Dark Matter Anomaly. Sharing President Rillak’s concern that Burnham’s love for Book could leave her “emotionally compromised” in the event she must make a hard call, Admiral Vance sends along a Federation security officer empowered to intervene if needed: Commander Nhan.

Despite their genuine joy at seeing each other again, Nhan assures Burnham that, as a Barzan, Nhan will let nothing keep her from doing her duty. She reveals she has a last resort tactical program that will destroy Book’s ship and will order its use if necessary. Burnham urges patience so Stamets can calculate how long the DMA will remain to mine boronite in its current, unpopulated location. That window of time, in which no worlds will be threatened, could be a chance to make Book and Tarka stand down.

Discovery’s first encounter with Book’s ship ends in near-disaster. Saru, Dr. Culber, Rhys, and Bryce take a shuttle to try to board Book’s ship secretly, to deescalate the situation, and take the ship peacefully. But Tarka didn’t tell Book he installed an autonomous defense system. It destroys the Discovery shuttle, and the crew aboard barely beam back to Discovery in time. Tarka is worried Book’s feelings for Burnham and the Discovery will jeopardize their quest to destroy the DMA.

At the DMA, Discovery and Book’s ship match each other jump for jump, Burnham always denying Book’s ship a clean shot at the controller. Tarka decides he’s had enough and fires a full spread of torpedoes at Discovery. Nhan wants to use her last resort option, and it looks as though Burnham might agree, but Stamets delivers the data showing the DMA can be expected to stay where it is for a week. Burnham convinces Book to wait a week, time the Federation will use to make peaceful first contact with Species 10-C. If, at week’s end, the Federation’s plan fails, it will back Tarka’s plan to destroy the DMA.

Although Book agrees to this compromise, Tarka does not. He beams his weapon into the DMA controller, destroying the anomaly. Unfortunately for him, his plan to protect the power source he needed to get back to his own universe doesn’t work. The DMA was being powered from outside our galaxy, on the other side of a wormhole—and a new DMA has appeared in its place. Ready or not, humanity has made first contact with Species 10-C.

“Rubicon” is a tightly paced and finely balanced episode of Star Trek: Discovery.

Concerns about Book and Burnham’s closeness to each other affecting their respective missions gives the episode a pleasing symmetry. The visual effects, reliably cinematic in scope, underscore this balance as we watch their two vessels jumping in response to and ultimately firing on each other. The “cat and mouse” battles in the DMA’s vicinity match Star Trek II’s battle in the Mutara Nebula for suspense and even surpass it for emotional impact, since we know both primary combatants well and have come to care about them almost as much as they care about each other.

The plot elegantly dramatizes Starfleet and the Federation’s commitment to compromise and peaceful resolutions. These high ideals are easy to talk about but, as Star Trek Discovery repeatedly shows, not always easy to live out. Burnham’s choice to literally put herself on the line—in a shuttle in front of Book’s ship—to send him the new DMA data and to propose Starfleet’s “middle ground” plan is one of this season’s most inspiring moments to date.

Consequently, Tarka’s “clear-headed” choice to scuttle it by destroying the DMA is one of the season’s most gut-punching, second only to Kweijan’s destruction in the season premiere. And unfortunately, it distracted me from fully appreciating either of the “tag scenes” that followed it.

The return of Rachael Ancheril as Nhan is welcome, but the full depth of her farewell to Burnham at the episode’s end is lost, at least on a first viewing, because audiences haven’t been given the space to process the DMA’s destruction. Likewise, Saru’s request for dating advice from Dr. Culber is undeniably amusing and endearing, but seems too abrupt a tonal shift in the episode’s epic final act, as even the characters (or the writers, through them) acknowledge.

But on the whole, “Rubicon” is a much more engaging, satisfying, and logical progression of the Star Trek Discovery story arc this season than was last week’s episode. Here’s hoping the show can keep the momentum going as we head toward more revelations about Species 10-C.