Picking right up on the heels of last week's cliffhanger, Lorka is given orders to return to the safety of the nearest Starbase at once. He seemingly complies, traveling by Warp instead of the spore drive, and thus gives his team time to devise a plan to save Pahvans from being destroyed by the Klingons. He also directs Stamets to have a full medical evaluation to provide cover for the reason they didn't use the spore drive to retreat. Stamets reluctantly complies.
Burnham, Tyler, and Saru devise a plan to return to Pahvo and beam two officers aboard and place sensors on the bridge of the Klingon ship after. They have a small window to do this after it's cloak comes down and before its shields go up. Burnham and Tyler convince Lorka that they are the best choices to be sent over. Meanwhile, Culber's medical examination of Stamets turns up troubling results. The spore drive jumps appear to be remapping parts of Stamets brain. Lorka orders Culber to send the results to him alone, then pulls Stamets aside to tell him about the plan to get behind the Klingon's cloak. In order to rapidly acquire the data they need, Stamets will have to perform 133 micro jumps with the spore drive. Here we also get our first bit of foreshadowing when Lorka reveals the data he's been gathering from each one of their jumps. With each jump they leave behind scattered pockets of negative mass. Stamets comments that these "could be alternative universes."
As the Stemets prepares for the jump, Tilly spills the beans about Stamets undisclosed symptoms to Culber. This opens an immediate gulf between them, but there is no time for them to talk about it. In rapid succession, with Culber monitoring Stamets condition, the Discovery jumps back to Pahvo to face the Klingons. As soon as the Kol orders the Sarcophogus to drop it's shields, Michael and Tyler beam over. Discovery then performs the first series of rapid jumps, firing weapons at the Sarcophogus from multiple angels and forcing the Klingons to retreat back under their cloak.
On the Sarcophogus, Burnham and Tyler quickly find out that there is another human on board. At Burnham's insistence, they make a slight deviation in their plans in order to save one of their own. They break in and find Admiral Cornwell, who is near death from her fight with L'Rell. Burnham is able to reviver her, but she is unable to walk. On the other side of the room, Tyler comes face to face with his captor L'Rell. The encounter sends him into a state of shock. Burnham acts quickly to take out L'Rell, but must now complete the mission without Tyler. She leaves him in the care of the Admiral and goes to the bridge.
Meanwhile, the Discovery starts its series of 133 microjumps in order to gather the needed date on the Klingon cloaking device using the Spore network. Culber watches as Stamet's heart rate skyrockets. When he asks him how he's doing, Stamets replies in a tranclike state "there's a clearing in the forest, that's how they go." As of the episodes end, we still don't have a full context for this line. Given the episode's title, it seems like a safe bet that this is another bit of foreshadowing.
Back on the Sarcophogus, Cornwell talks Tyler through his shock as he relives his past trauma as L'Rell's prisoner. Burnham places the last sensors and hides within earshot of the bridge. This is the first time we see the Klingon's speaking to each other in English, thanks to Michael's Universal Translator. When she realizes Kol is not falling for the trap, she reveals herself and challenges him to a fight in order to buy time. Being a Klingon warrior, he cannot resist the honor of killing the one who murdered T'Kuvma. Burnham's Vulcan martial arts training comes in handy, and she is able to buy enough time for the Discovery to complete it's jumps. She is gloriously beamed aboard after snatching Captain Georgiou's badge from Kol's armor. Tyler and Cornwell are beamed back safely too, but L'Rell manages to tag along at the last minute.
The Sarcophogus, cloaked and unshielded, is promptly destroyed as soon as the away team is safely aboard. In a fitting explosion, the Klingon ship that started the whole war is finally destroyed. While the war is not won, this was a decisive victory for the Federation. This comes as mixed news for Lorka, as the return of Cornwell means he is likely to lose his command of Discovery.
After the dust has settled, Ash confides in Michael about the sexual trauma he endured at the hands of L'Rell in order to survive Klingon captivity. How he doesn't regret it, because it's how he survived, but his PTSD is real. The scene itself is really powerful. The show has been remained consistent in depicting the true ugliness, brutality, and lasting damage of war.
Several rapidly paced changes take place within the last few minutes of the episode. Staments agrees to make one final jump to get the crew back to safety, but he informs the captain that he will no longer be able to make jumps. He owes it to his partner to step down so that Starfleet Medical's finest doctors can finally look into the effects the spore network has had on him.
Meanwhile, Ash tosses and turns through another nightmare of being being with L'Rell. This is by far the most disturbing depiction of the sexual violence he endured. He wakes up with Michael next to him, and decides to go to the bring to confront L'Rell. Their exchange opens up a lot of questions. When Tyler demands "What did you do to me?" L'Rell responds in a soothing tone: "Do not worry... I will never let them hurt you." They are interrupted by the ship announcing a Black Alert. As Tyler turns to leave, L'Rell gives the one work response: "Soon..."
Back in engineering, Stamets and his Culber make plans to go to an opera once they return to starbase. As Stamets is about to go into the chamber, we finally get the kiss we've all been waiting for. The joy is short lived, however. The order for the jump is given, but something immediately goes wrong. Stamens screams out in pain. Tilly announces that the ship experienced an "incomplete navigation sequence." Saru announces he cannot pinpoint where they are. Culber pulls Stamets from the Spore Drive chamber; his eyes are glowing blue and he is mumbling incoherent phrases: "so many... I can see them all... infinite permutations..." The episode closes with a slow zoom out of Discovery in space surrounded by the wreckage of a seemingly huge unknown ship.
There are a couple of theories floating around out there worth considering. The first is that Ash Tyler is really Voq, last seen with L'Rell in episode 4 after losing command of the Sarcophogus to Kol. There are plenty who refute this theory, and I would count myself among those who would be disappointed if that were the case. Especially after the depth they just revealed in his character. There is also the theory, backed up by Stamets foreshadowing lines, that they have just transported their entire ship into the infamous Mirror Universe. The brief preview that aired afterwards didn't give too much away, so we will have to wait until January to find out.