“Broken Pieces” opens in 2385—fourteen years before Picard’s 2399 setting—on a mysterious planet named Aia, “The Grief World,” where the half-Vulcan, half-Romulan Starfleet infiltrator Commodore Oh (Tamlyn Tomita) leads Zhat Vash recruits through a ritual called “The Admonition.”

The Admonition involves connecting to a “storehouse of preserved memories,” discovered by the foremothers of the Zhat Vash, which forces on new recruits the revelation of “the grim fate of the civilization that perished here long ago.” The ritual, Oh tells the assembled Romulan agents (including some familiar faces), may drive some of them mad.

“We have worked in shadow to prevent a second coming of the Destroyers,” Oh says. “Witness the devastation that must be prevented. Endure The Admonition, if you can.”

Viewers don’t bear the full brunt of The Admonition like the Zhat Vash recruits, only a handful of quick-cut shots: an android’s face (which dissolves quickly into Data’s open, yellow eyes), a planet exploding, mysterious life forms, a rotting fox—but the trauma on the Romulan agents is soon manifest. One Zhat Vash inductee shoots herself, another beats herself to death with a rock, while a third rips her own face open with her fingernails. Only Narissa (Peyton List) comes out unscathed, an early sign of the calm and zealotry she will bring to her mission, years later, while stationed aboard the Borg “Artifact.”

Part of The Admonition was seen previously on Star Trek: Picard, when Commodore Oh, in her guise as the head of Starfleet Security, forces a Vulcan mind meld on Dr. Agnes Jurati (Alison Pill) in the series’ third episode. Jurati is so traumatized by her taste of The Admonition that she murders Bruce Maddox (John Ales), the AI researcher who created Soji and Dahj, by building on his collaboration with Data begun in The Next Generation episode “The Measure of a Man.”

In “Broken Pieces,” Agnes fills in some of the details, providing us a nearly complete picture of exactly why the Zhat Vash are convinced synthetic life must be eliminated from the galaxy (though we’re still unsure why they didn’t come after Data, decades earlier).

After the flashback to the Zhat Vash ritual, “Broken Pieces” returns to the unregistered speed freighter La Sirena, the ship captained by traumatized former Starfleet officer Cristóbal Rios (Santiago Cabrera) and chartered by Jean-Luc Picard (Patrick Stewart) to rescue Soji. When Soji is first beamed aboard, Rios is shocked, for reasons we soon learn: Soji is the mirror image of a woman named Jana, who Rios saw killed years earlier. Thanks to Commodore Oh’s infiltration of Starfleet Security, a “Black Flag Directive” sent to each Starfleet captain, instructed them to kill, on site, synthetic life forms contacted in space. Rios’ beloved captain performed what Starfleet’s secret directive required of him, but was overcome by guilt and died of suicide.

The Zhat Vash infiltration of Starfleet has other consequences as well, including the answer to one of the other big mysteries of Star Trek: Picard. The events of the series are precipitated, years earlier, by a 2385 attack on the Utopia Planitia Fleet Yards on Mars, which is blamed on synthetics. The United Federation of Planets responds by completely banning research into synthetic life, driving Maddox to continue his research in secret. The series has hinted from the beginning that someone else may have been responsible for the attack, but “Broken Pieces” makes it plain: the attack on Mars was a false flag attack by the Romulans.

That probably won’t come as much of a surprise by this point in the series. But there are still a few aspects to the Zhat Vash plot that remain obscured.

Late in the episode, the La Sirena crew sit down to a meal and put together the pieces of the greater conspiracy they each hold. Somewhere out there is an “octonary” system, with eight stars in an artificially constructed configuration (readers of Cixin Liu’s The Three-Body Problem will have a sense of the astonishing complexity inherent to such a star system). The system was built by an ancient species, “thousands of centuries ago” Agnes tells us, whose “hubris” lead them to create artificial life. It was a disaster, so they left The Admonition behind—marked by the octonary stars—as a warning to future species attempting to develop their own synthetic life.

Raffi starts the explanation, from hints she pieced together with the help of the ship’s various holographic subsystems: “This warning says: don’t do what we did. We created synthetic life forms and—”

“They evolved, and it did not go well. At all,” Jurati says, finishing the thought.

“Apparently, these people believed there was a threshold of synthetic evolution—a dividing line,” Picard says. “The Romulans, it seemed, took this Admonition very seriously. They created a group, the Zhat Vash, dedicated to finding and terminating all synthetic life.”

But here’s where it gets strange. Because it seems the threat isn’t the synthetic life itself, but instead what its creation will eventually prompt. Rios compares it to a deadly version of what happened when Zefram Cochrane activated Earth’s first warp drive in 2063, which caught the attention of a Vulcan starship, leading to our first contact with an alien civilization and, eventually, the United Federation of Planets.

“Like the Zefram Cochrane warp drive,” Rios says. “When you cross that line, somebody shows up.”

“Somebody really bad,” Jurati agrees.

Who or what might arrive to destroy humanity should they create synthetic life remains a mystery. All we know is that the Romulans believe Soji is the Destroyer, destined to break about these terrible consequences if the Zhat Vash fail in their mission.

At the end of “Broken Pieces,” Jean-Luc, Rios, Raffi, Agnes and Soji set out for the hidden world where Maddox created his synthetic life. Picard is optimistic that they’ll be able to find a better path than the Zhat Vash.

“The past is written, but the future is left for us to write. And we have powerful tools Rios: openness, optimism and the spirit of curiosity. All they have is secrecy and fear,” he says.

Unfortunately, unbeknownst to them, Narissa follows them into the warp conduit, setting up a final showdown in Star Trek: Picard’s concluding two-parter “Et in Arcadia Ego,” the first half of which will premiere on streaming service CBS All Access on Thursday, March 19.