Taking its cue from popular series and the grittiest episodes in the franchise canon, Star Trek: Picard infused its dramatic narrative with a number of dark moments. Over the past few decades, the franchise has tried to find an equilibrium between being an optimistic representation of humanity's best intentions, and a stark reminder of its worst. In the '90s Deep Space Nine notably dived into the process more fully with its revealing look at the ambiguity in Starfleet morals during the Dominion War storyline, and recently Star Trek: Discovery spent much of its first season wrestling with the ramifications of the Mirror Universe.
Star Trek: Picard has chosen to follow a more cynical plot, taken from topical current events despite the fact that it features at its center one of the most profound examples of integrity: Jean-Luc Picard. Though it takes place in the 24th century, the series features a very jarring homage to Game of Thrones, with many of its most emotional moments coming at the expense of characters' lives.
DAHJ'S DEATH
Star Trek: Picard begins with a sense of foreboding as viewers are introduced to Dahj and her boyfriend. They are enjoying a quiet evening before a group of unidentified men suddenly break in trying to kill them. They succeed in killing her lover, but Dahj manages to escape and locate the reclusive Jean-Luc Picard.
Their meeting is brief and perfunctory, as no sooner does she elicit the former admiral's help than she's killed by the same group of paramilitary personnel in a gruesome explosion. This traumatizes Picard, but also acts as a catalyst for him to find her twin sister and assuage his guilt for not being able to protect her better.
RAFFI'S RELAPSE
Many of the characters on the series are emotionally damaged, including the intrepid Jean-Luc Picard, but the most transparent of them is Raffi. After Starfleet terminated her position, the conspiracy theories concerning the synth revolt on Mars that pushed her away from her husband and her son slowly ate away at her mind.
Raffi began a solitary existence of feeding vices that only made her more isolated. She drank and smoked heavily, habits she didn't quit even when agreeing to help Picard find Dahj's sister. When Raffi was finally reunited with her adult son, the reunion was anything but a happy one, causing her to relapse. Raffi nearly lost everything she'd worked hard to achieve until she threw herself into helping those who would accept her.
COMMODORE OH'S DUPLICITY
When viewers first meet Commodore Oh, the Head of Starfleet Security, she comes across as any other half-Vulcan officer: stoic, resolute, and officious. However, the other half of her genetics is Romulan, and she's revealed to be a plant for the Empire. More egregiously, an agent of the Zhat Vash intent on wiping out all synthetic life in the universe.
She singled out Dr. Agnes Jurati to do a Vulcan mind meld, showing her all of the horrors synthetic life intended to inflict on organic life in the future if the Zhat Vash didn't stop them. It was a shocking revelation that corruption had infiltrated Starfleet and the Federation at the highest levels.
NAREK BETRAYING SOJI
Feigning interest in the research being done by Soji Asha on the Artifact, an abandoned Borg cube better known as the Romulan Reclamation Site, Narek was able to find a way into her private circle. A Romulan spy, his mission was to ingratiate himself romantically to Dr. Asha to learn about her true identity as a synthetic lifeform.
Once he made Soji believe that he loved her, he set about using the Zahl Makh (a Romulan meditation ritual) to get her to remember early trauma in her childhood. By reliving the past, she came to the shocking realization she was a synth, not a human. Narek then "activated" her in the meditation chamber with noxious gas.
THE SYNTH REVOLT ON MARS
One of the earliest and darkest moments in Picard is first only described, left to hang over the series like a solemn shroud, until it is finally shown in horrific detail. It involves the synth revolt in Mars, which was said to be part of a Romulan act of treason coinciding with the Romulan Refugee Relief Effort.
The Relief Effort was stopped when it was revealed that the Romulans had hacked the synthetic drones on Mars, and Starfleet put all its energy into stopping their efforts, but thousands of lives were still lost. It was one of the darkest moments in Federation history when Starfleet used the event to both turn its back on Romulan refugees as well as ban all synthetic lifeforms from existing.
SEVEN LOSING ICHEB
After Seven of Nine had been acclimated to life aboard the starship Voyager she found an unusual duty to perform as part of its crew: help several young Borg drones adjust to life outside of the Collective. One Borg drone known as Icheb became like a surrogate son to her, and they shared a close bond.
In the most graphic scene in the series Icheb, now a young man assisting Seven and the Fenris Rangers, has his Borg components forcibly removed by criminals. As they hunt for his cortical implant, which he had removed in Star Trek: Voyager to save Seven's life, they drill straight into his skull. He dies in horrible agony in Seven's arms.
HUGH'S SACRIFICE
Once known as Third of Five, a Borg drone who expressed uncharacteristic individuality in Star Trek: The Next Generation, Hugh was given his name by Geordi La Forge. As Hugh slowly became comfortable with his own autonomy, Captain Picard helped him realize he and other like-minded Borg could create a life for themselves independent of the Collective.
When Picard meets Hugh again, he's the Director of the Borg Reclamation Project aboard the Artifact. He helps Picard locate Soji and escape with her, an act which all but ensures his fate is sealed by the Romulans. He is killed by Narissa for in an unnecessary act of violence that fans felt made no narrative sense.
AGNES KILLING MADDOX
Dr. Bruce Maddox was not only the brilliant mind behind refining the creation of flesh-and-blood synthetics through the process of fractal neuronic cloning — he was also the love of Dr. Agnes Jurati. It made his murder at her hand one of the most upsetting moments in Picard, and transformed the narrative arc of her character completely.
When Commodore Oh revealed what synthetic life was capable of doing to Jurati, she felt like she had no choice but to kill Maddox and prevent him from being able to help them accomplish their goal. She suffocated him while he was in Sick Bay aboard the La Sirena, and nearly got away with it until Raffi revealed her crime to the crew.
SUTRA TURNING THE SYNTHS AGAINST THE ORGANICS
When Picard and co. finally reach Soji's home planet, the world containing the rest of the rumored synthetic race, they're in for quite a surprise. Not only are there dozens of synthetics pairs, but Dahj and Soji had a sister who had remained there after they'd left: Sutra.
Sutra was programmed by Maddox, and developed some obstreperous behavioral patterns. She turns Dr. Alton Soong and Agnes Jurati against Picard and his friends, to the point where she even has Soji believing that it would be better if the synthetic race fulfilled its Romulan prophecy and destroyed any enemies to its way of life.
PICARD'S DEATH
In the explosive series finale, Picard's Irumodic Syndrome has started to cause his neurological faculties to deteriorate to such a degree that in the middle of a stand-off between the Romulans and Starfleet, it's apparent he might actually die. Patrick Stewart read the script and believed his character to be killed off.
The tail end of the episode emphasizes the grief of everyone Picard is close to. In contrast to Data's passing, which is dignified and poignant, Picard's is harrowing and depressing until the shocking twist.