Diethard reports to Lelouch over the phone about Black Knight activity, such as maintenance on the Guren, recruitment and infiltration into Britannian warehouses, arrests, and the search for Tohdoh and the Holy Swords. After hanging up, Lelouch meets with an incognito C.C. at the airport. She’s unsure about being his representative to meet with the Chinese, and he walks off, unaware that he’s being watched by Mao. Lelouch then recalls a time after the war when he carried Nunnally on his back and walked with Suzaku through a field of corpses in a devastated town. Nunnally asked about the strange smell, and Lelouch lied and said it was a nearby garbage dump. Suzaku, however, stopped walking and broke down into tears. The next day, Suzaku greets Lelouch at school and chides him for not coming to class more often. Lelouch tells Suzaku he should come over for dinner more often because Nunnally is lonely. Their conversation is suddenly interrupted when Rivalz pulls up in his motorcycle and asks Lelouch if he knows about Milly’s matchmaking session. Lelouch decides to run home and tell Nunnally that Suzaku is coming over for dinner. Nunnally hears a door open and assumes it’s Sayoko, but it’s really Mao. Elsewhere, Milly meets Lloyd at the Lancelot hangar for their matchmaking session. He asks her if it’s weird to meet in such a place, and she says he’s a unique person, especially for willing to meet with someone from the disgraced Ashford family. Cecile brings tea, and Lloyd dispenses with formality and casually asks Milly to marry him, then asks her if she wants to put it off. Back at home, Lelouch is shocked to find a picture of Nunnally tied up in her wheelchair. He then gets a phone call and briefly speaks with Nunnally until Mao takes over. Lelouch says that C.C. is gone, and Mao explains that’s why he’s taking action, because a Geass-immune person can be a nuisance. He say’s he’s alive thanks to Britannian medical science, but also because Lelouch issued the order to “shoot” rather than “kill.” Lelouch knows that Mao is within 500 meters of him, and Mao decides to make it a game by giving Lelouch five hours to find him, without police interference. At lunch, Rivalz tells Kallen and the rest of the student council about Lelouch and Shirley’s “stranger” game. Lelouch suddenly runs into the room and leaves just as quickly. Mao calls Lelouch and gives him an extra hour. Ohgi returns to his apartment and finds Viletta cooking. He asks her if she remembered anything, but she hasn’t . Suzaku approaches Lelouch and sees the picture of Nunnally. He asks if it’s connected to their Britannian identities, but Lelouch explains it’s just a bully. Lelouch remembers hearing water in the background, and Suzaku concludes it must be the underground circulation system. They find a machine gun camera waiting for them downstairs, so Suzaku runs up the wall and kicks it. They find Nunnally in a large chamber with a motion-sensitive bomb swinging over her head, which Suzaku volunteers to disarm.
Sayoko shops for groceries and gets a call on her cell phone. Mao sits in the school’s chapel and is annoyed by the students’ thoughts. Lelouch enters the chapel, and Mao gloats over him not being able to do anything about the bomb. He’s set up their final contest, which will be a chess game. Elsewhere, Cornelia sits in a garden with Euphemia and teases her about her weight. Euphemia comments that Clovis’ garden looks like Marianne’s, and they recall the times Lelouch used to quarrel with Clovis. Cornelia wants to stabilize Area 11 and capture Zero quickly so that she doesn’t disappoint Clovis, Lelouch and Nunnally. Mao shows Lelouch a scale and explains that each side is wired to the bomb’s detonating and dismantling switches. Captured pieces are placed on the scale. If Lelouch wins, Nunnally is saved, but if Mao wins, the bomb explodes. As the game progresses, it naturally swings in Mao’s favor. Lelouch tries to think of seven things at once to confuse Mao, but Mao can easily tell the truth since his Geass is focused solely on Lelouch. With the scale almost totally on Mao’s side, Lelouch panics and gives up. Mao says he can’t hear him, and Lelouch admits that he’s lost. Mao says he’s happy to hear the real thoughts from Lelouch’s heart, but he checks him anyway and tosses the last piece on the scale. He checks his video monitor to see the aftermath and is shocked to see Nunnally alive and the bomb unexploded. Just then, Suzaku smashes through the window and punches Mao. Mao sees that Suzaku timed his movement with the bomb’s swinging, and Suzaku says Lelouch told him which wire to cut. Lelouch doesn’t remember that, but he looks at his reflection in his phone and realizes he used Geass on himself. Lelouch mentally tells Mao that he used Geass on himself to forget what he told Suzaku, thus allowing his thoughts to trick Mao. Sayoko unties Nunnally, and Suzaku tries to put Mao under arrest. Mao calls Suzaku a father killer and reveals that Suzaku killed Genbu seven years ago because he thought it would end the war quickly, as Genbu wanted to begin resistance against the Britannians. Mao says that Suzaku is a murderer and puts his life on the line to save his own heart, hoping he’ll get killed in the process. Lelouch then uses Geass on Mao to make him shut up. Mao stumbles outside the chapel and finds C.C. waiting with a gun. She tells him she loved him once and shoots him in the neck. Inside the chapel, Lelouch looks at Suzaku, who was shocked in place by Mao’s words.
There’s the old cliche that the third time is the charm, but that isn’t the case here with Mao. In episode 14, his plans were thwarted in the end by the appearance of C.C. Last episode, he was outmaneuvered by Lelouch and went down in a hail of bullets that should’ve killed him. Instead, he’s somehow miraculously survived and come back for revenge by kidnapping Nunnally. But what Lelouch said last time about his simplistic thinking hasn’t changed, and he’s able to trick Mao again by using Geass on himself to forget important information. Viletta’s amnesia continues, and Ohgi is drawn in more while trying to figure out what she knows about Zero. We get to see a different side of Cornelia when she spends some private time with Euphemia. She’s been the serious commander bent on capturing Zero up to now, but privately she’s much nicer. And given their conversation, it’s clear that she thought favorably of Lelouch and Nunnally. The big surprise in this episode is the revelation that Suzaku killed his own father during the invasion seven years earlier. Lelouch is surprised to hear it, and the public announcement of that knocks Suzaku into being catatonic. While that’s all interesting, it’s book ended by what is pretty much a repeat of last episode. While Mao served as an interesting warning to Lelouch about the dangers of Geass gone wrong, it really should’ve ended in the last episode. Bringing him back again and killing him off was just a waste of time.