Summary: Ro investigates Thriss's death. Dr. Tarses finds that a hypospray of arithrazine, used to treat theta-radiation exposure, is the cause of death. Councillor zh’Thane tells them to leave, and to consider their quarters off-limits. Ro tries to offer condolences, and Anichent attacks her, though he backs off immediately.
The Defiant encounters a large ship attacking a much smaller ship. Only the smaller ship replies to hails, but it's crew consists of insectile creatures chittering in a language that the universal translator can't translate. When the larger ship attacks the Defiant as well, they traget its weapons systems and it flees. Vaughn starts beaming aboard some of the wounded creatures for treatment, which freaks them out even more. Dr. Bashir is on a survey aboard the shuttlecraft Sagan, but it can't be reached.
Kira returns to DS9 after her 2 week trip to visit Kassidy on Bajor. She is accosted by 2 hooded Bajorans, who thank her for releasing the Ohalu books; they say that she has revealed to them a destiny long obscured by those in power.
Ezri, Bashir, and Nog are in the shuttlecraft Sagan trying to determine the source of some dimensional distortions in system GQ-12475's Oort cloud when an enormous alien cathedral appears before them, phasing in and out of multiple dimensions at once. Nog says it's over half a billion years old. They try hailing it, and are surprised that after a minute it sends them a huge datafile. Before they can translate it, an arm extends from the cathedral and the shuttle is nearly swatted by it, but they just manage to escape. Once the dimensional distortion is gone, they get a message from the Defiant saying they need Bashir to treat some wounded aliens on board.
Cerin Mika, a former member of the Pah-wraith cult whom Gul Dukat once impregnated and tried to kill, has since become a peace advocate because of her bi-racial child. She tells Yevir that she's the niece of Vedek Solis, who is currently his biggest rival for kai, and an advocate for the Ohalu texts. She says she too is a member of Ohalu's truthseekers sect, and asks Yevir to lift Kira's Attainder, which he refuses. After seeing her child, he realizes why he's so drawn to the B'hala statue that Kassidy gave him: it has the facial features of both Cardassians and Bajorans. Yevir books passage to DS9 and comes up with a radical plan.
Bashir manages to triage most of the wounded aliens, but 3 of them couldn't be saved. He names them "kukalakas" after his stuffed bear. He realizes they're having trouble breathing because they're used to lower gravity, so he lowers it--but then accidentally knocks a floating exoscalpel into one of the aliens. They manage to save the patient (again), but Bashir wonders if the cathedral had some sort of effect on him. Nog also develops a severe itch in his artificial leg, that turns into screaming pain later on. Ezri feels mildly ill, then violently so.
Ro visits Shar's quarters to talk to his bondmates, as she needs to finish the report on Thriss's death, but they won't let her in; they're still grieving 2 weeks later. Ro, worried about whether Anichent is even still alive, uses a security override to enter, infuriating Dizhei; Ro finds that she's drugged him. Dizhei says it's to stop him from killing himself; their despair goes beyond the loss of a mate and into the possible end of their species. Ro apologies and leaves without filing her report.
Macet abruptly asks Kira to let the Trager depart from DS9 a few days earlier; she reluctantly agrees. Aboard the Trager, Vedek Yevir tells Macet to get the ship under way and that he'll explain ihs purpose there once they've gone.
Bashir rushes Ezri to sickbay; her isoboramine levels are falling steadily, and she's experiencing neural trama. Nothing he tries on her seems to help, and Bashir continues to experience more confusion himself. Shortly thereafter, Nog and Shar are beamed in with medical emergencies as well. Bashir has to remove Nog's artificial leg; his body rejected it, and is growing a new leg in its place. Bashir has some ensigns construct a medical transport pod suitable to host the Dax symbiont, and prepares her for surgery.
Bashir says goodbye to Ezri, and starts surgery. He extracts the symbiont, then accidentally injects it with isoboramine, instead of boramine, poisoning it. Julian searches his mind-cathedral for the antidote, and finds everything in disarray; though an old school rival, Dr. Lense, gives him the answer just in time. He kisses Ezri goodbye, and she wakes up, recovering rapidly instead of dying. Bashir passes out.
While pounding down root beer floats, Taran'atar tells Quark he wants to reserve holodeck time to talk to Vic, curious about how he saved Nog's life. The Trill diplomatic aide Hiziki Gard flirts openly with Ro, to Quark's chagrin. Sure declines a dinner invite, since she has plans with Quark, but finds herself thinking of him afterwards.
Shar and some other scientists show the alien aboard some hieroglyphs from the recovered texts in order to train the universal translator, and it it yells and cowers at a glyph seeming to represent the cathedral they encountered, calling it a cathedral/anathema.
Bashir and all the others from the shuttle are found to have the same quantum resonance pattern after passing through the interdimensional flux. Bashir is experiencing neurological degeneration, regressing to his state from before he was genetically enhanced.
The translators pick up enough to learn that the aliens are called the D'Naali. They say they are indebted for the help, and Vaughn asks if they can have a guide to continue mapping the Oort cloud. They agree to let Ryek’ekbalabiozan’voslu stay aboard--Sacagawea, as the crew have taken to calling him. They immediately head back to the cathedral, and scans reveal a hollow area inside. Before they can beam in however, they detect 13 ships approaching, of the type that attacked the D'Naali. The Nyazen ships setup a blockade, and tell Vaughn that he's defiling the cathedral. They also say that the D'Naali are their enemy, and begin firing on the Defiant.
Taran'atar visits Vic in the holodeck, but also finds Akaar there. Akaar tells him that he killed hundreds of thousands of Jem'Hadar during the war, Taran'atar is not intimidated, though he did no fighting in the Alpha Quadrant during the war. They have a discussion about faith, and Taran'atar seems to be starting to understand the concept.
Macet takes Yevir to Lakarian City on Cardassia, where they her with Cleric Eshoka of the underground religion Oralian Way. Yevir says they just broke peace before Bajor joins the Federation, and casts aside his earring and robes and offers his hand; shocked, Eshoka accepts. Unsure what the next steps are, Garak reveals himself and says he may have a solution.
The Nyazen attack and force the Defiant to retreat, but they don't pursue. Vaughn tells Nog to work on a way to beam a team into the cathedral without alerting them. Vaughn almost calls Ezri Lt. Dax, and she starts to wonder if she should now go by Ensign Tigan instead. She also thinks he should remove her as XO.
Nog confesses to Shar that he isn't exactly in a hurry to solve the mystery of the cathedral, as it likely means he'll lose his regrown leg. Shar finally confers that Thriss has killed herself.
On their date in the holodeck, Vic tells Quark and Ro that with Bajor's impending entrance into the Federation, they need to leave and go into business together.
General Lenaris tells Kira to join the Ohalavaru with him to get Vedek Solis elected. She says she's caused enough division amongst her people, but can tell Lenaris isn't going to let it drop.
The translated text reveals that the cathedral used to reside on an inhabited planet, but the artifact destroyed the planet. Its progenitor species were likely ancestral to the D’Naali and Nyazen, the artifcat built to mine energy from other universes. Sacagawea immediately surmises that they need inside the cathedral, and can tell by sight that Nog, Ezri, and Bashir have been "misaligned" by it; Shar says their quantum resonance patterns are becoming incompatible with the signature of their universe. Sacagawea says if they enter the cathedral--quickly--they can be restored.
Vedek Solis address the Assembly, imploring them to rescind the Attainder on Kira; they call for a vote, but it still fails. Mika tells Solis that she owes Kira her life, and the time to take act is now.
Ezri asks Vaughn to relieve her of duty, but he denies her request, saying that it was Ezri who graduated Starfleet Academy and enrolled in command training, not Dax; and also, that it would be a blow to morale on the ship. She gratefully returns to duty.
Nog proposes a solution to get into the temple by using self-replicating transporter relays that the Nyazen won't be able to easily detect because of the Oort cloud. It's risky, but during the meeting those impacted by the cathedral blink out of existence briefly, and they realize they have little choice but to act now. Julian records in his log later that he was in the other reality for much longer than the others, and was surprised to find he was quite happy there, with a wife and kids.
Garak takes Macet, Yevir, and Ekosha to a secret Obsidian Order facility in the highly irradiated Cardassia City.
The away team manages to beam aboard the cathedral without having their matter scattered across space, but the Nyazen immediately detect the transporter signal and interpret it as an energy weapon. They chase the Defiant out of the system, causing it to lose the transporter lock.
I'm the Bajoran shrine on DS9, a dozen plus Ohalavaru throw down their earrings and take up silent protest for Kira. The Orthodox Bajorans start to threaten violence, but Kira herself tells the demonstrators they're being taken into custody. Afterwards, she learns these demonstrations occurred in every province on Bajor. Ro tries to convince Kira that she did the right thing by giving her people a choice. She also tells her that she's resigning once Bajor enters into the Federation. Kira flips her desk and has a breakdown.
In the cathedral, Ezri is faced with an alternate life where her brothers died and she takes over the books for the family mining business. She eventually realizes that isn't where she's supposed to be, and decides to stick with Starfleet. She signals for the Defiant to beam her back, having aligned her worldlines.
Nog finds himself back on AR-558. Taran'atar cuts off his leg, then throws down a comm badge that Nog uses to signal the Defiant.
Dax is back in the pools of Mak'ala, though he's afraid of monsters with razor sharp teeth. He encounters all his past hosts, who convince him to join back with Ezri, against his wishes, lest his nightmare of millions of dead bodies come true.
On the morning of the Bajoran ceremony, Macet and Yevir return to DS9 unannounced on the Trager.
Julian finds himself back on Adigeon Prime, reliving his past, but with an Alice in Wonderland theme. He finds young Jules about to undergo his genetic enhancement procedure and rescues him, which should have prevented him from becoming smart again, but he finds all his acuity has returned. Jules tells him that now he's resolved his issues with his younger self. He is admiring his fully restored mind palace when he is beamed back to the Defiant.
Yevir addresses a crowd on the promenade. He says the Cardassian and Bajoran governments have failed to unite their people, so the respective religious sects of both peoples decided to work outside the government to make it happen. He then reveals that on their trip to the Cardassian city, they recovered the 4 lost Tears of the Prophets: the Orbs of Truth, Destiny, Souls, and Unity. Afterwards, Ambassador Lang contacts Asarem about restarting negotiations, but Shakaar shrugs it off, saying the Federation can handle it.
A fleet of D'Naali ships arrives and drives off the Nyazen attackers. They have an organ that allows subspace telepathy, and they were communicating with Sacagawea the whole time he was aboard. They want transporter technology so they can destroy the cathedral; when Vaughn refuses, saying it would upset the balance between the D'Naali and Nyazen, they threaten to take it by force. Vaughn has Sacagawea beamed back aboard their ship and they make a run for the cathedral.
When Vaughn explains the situation to the Nyazen commander, he agrees to let them beam their people back, while they engage in a fire fight with the D'Naali. With the help of the Defiant, the D'Naali quickly retreat; however, the transporters are knocked offline, and the Nyazen quickly turn on them again. Shar suggests using the Sagan's teleporters, and they beam back all of the away team. Nog's leg is gone again, and Ezri and Dax are near death. Bashir immediately preps for surgery.
Joseph Sisko has been in bad shape since his son and grandson disappeared. He ran out of heart medicine and didn't bother to get it refilled. A member of the kitchen staff finds him sprawled out on the ground in the garden.
As Shakaar is about to sign the Federation ceremonial parchment, Hiziki Gard throws a concealed blade at Shakaar's neck, nearly severing his head clean off. He smiles at Ro and beams away. Shakaar is dead.
Review: Book 3 was a bit overlong and dragged a bit, but overall it was enjoyable. I really popped for the return of Garak, even if his role was small, and the assassination of Shakaar was somewhat shocking--even though you just knew it wasn't going to go off without a hitch. Really seemed like a middle story though--wrapping up what happened in the previous book while setting the stage for what happens in the next one.