In a flashback to September 14, 2025; Sinon, who had accidentally fallen down a trap chute while navigating a dungeon below SBC Glocken, discovered a boss-class monster and decided to at least try to defeat it before it killed her. To her surprise, the position she chose for her attack was just out of the monster's attack range, thus, by conserving her ammo and accurately hitting the boss's weak spot without missing even once, she was eventually able to defeat it after three hours and acquired a new sniper riffle, the PGM Ultima Ratio Hecate II.
Three months later, on December 7, 2025; Sinon, who had been invited to Dyne's PvP squadron two weeks before, was called upon to kill the supposedly only person in a Mob hunting party that had a live-ammunition gun and posed a threat in PvP. The ambush was to take place in a wasteland area, but the mob hunting party had not shown up at the expected time.
One of the squadron's members, Ginrou began wondering whether the squadron had changed their route, since they had previously wiped out that same squadron the week before. Dyne reassured them that the hunting party would show up, because he had checked their route himself, and that players become careless again several days after the last incident. He went on to explain that mob hunting parties were usually equipped with energy weapons, which would not be much of a problem with their Defense Fields. In addition, the squadron could only afford a single player with a physical weapon for support, which would be the person Sinon would target with her sniper, making use of the no Bullet Line for a sniper's first shot rule.
Ginrou added that if Sinon were to miss, he would be the person to give her the minute needed in order to change location and reset the enemy's ID information. Afterwards, Ginrou decided to ask Sinon to go on a date after the encounter. After Ginrou's failed attempt to do so, Dyne told Ginrou to stop bothering Sinon, but at that point the squadron's spotter quickly noted the arrival of the hunting squadron.
The squadron was composed of five players with energy weapons, one player with a Minimi, and one player in a mantle who had not been on the battlefield the previous week. Although one of Dyne's members wondered if the player was Death Gun, Dyne reassured him that he was a support player who put his skill points into strength to be able to carry extra items such as extra ammunition, energy packs, or earned items, thus he would not be a problem during the main attack.
Sinon requested permission to attack the man in the cloak first with her first shot, due to his unknown status. Dyne told her to follow the original plan and attack the Minimi user first on his command. Sinon agreed to it, but insisted to use a second shot against the man in the cloak. Afterwards, Dyne and his men proceeded to get in position. After a few moments, Sinon gave word that the mob hunting squadron was about 400 meters from Dyne, and 1,500 meters from her. Dyne, trusting her to get a hit at such a far distance, gave Sinon permission to open fire.
Although Sinon successfully sniped the player with a Minimi, the new player in the party turned out to be armed with a GE M134 Minigun, leaving Sinon in disbelief as she realized that the Mob hunting squadron was not late because the squadron's hunt that ran long, but because it had been the Minigun and its ammunition slowing the second physical weapon support player down. Watching as her unaware squadron closed in for the kill, taking out a couple of energy weapon players. However, at that point, the cloaked man began the slaughter of Dyne's squadron, Ginrou being the first to die. Sinon decided to personally kill the bodyguard, as she believed that he was strong since he was able to smile on the battlefield, thus killing him would help her become stronger.
Sinon ran down to her companion's cover while dodging the incoming bullets fired first from the energy weapons, and then from the Minigun. When she reached Dyne and his men's cover, Dyne revealed that the man with the Minigun was a bodyguard hired by the mob hunting squadron, named Behemoth. Sinon brought up that his Minigun may be running low on ammo, and thus if they attacked all at once, he might hesitate to go all-out. She ordered Jin and Miso to attack from the left, while she and Dyne would attack from the right, and Arashi would stay behind as backup.
Dyne intervened, claiming that there were still three players with energy weapons, thus a head on offensive would render them useless, and the Minigun would surely mow them down. Believing finishing the job was a lost cause, Dyne even suggested logging out in order not to face defeat in the eyes. Sinon, angry with Dyne, told him to at least have the courage to die at gunpoint in a game.
Afterwards, the group decided to continue with Sinon's plan and began the final assault. However, Behemoth was able to spot Sinon just as she had him in her sights, thus he was able to dodge the shot, though at the loss of his goggles. Just as Behemoth revved the Minigun for firing, Dyne managed to shoot him in the arm, causing Behemoth to miss his target, which allowed Sinon to get to cover. Dyne then decided to charge towards the enemy in order to throw a plasma grenade, which blew up one enemy and stunned another one, at the cost of his life.
Using the momentary cover created by the explosion, Sinon decided to move to a tall building to snipe at Behemoth from. However, as Sinon got into position and began looking for Behemoth, she was surprised that Behemoth had predicted her course of action and was already targeting her. Leaping off the building to escape and losing a leg in the process, Sinon was able to enter Behemoth's blind spot immediately above him, where the minigun could not be aimed at due to being mounted on a rail. While in mid air, Sinon used her sniper to kill him with a headshot.
Meanwhile, in ALfheim Online, while Leafa, Lisbeth and Silica were hunting mobs to get materials for Lisbeth, Kirito and Asuna were enjoying their time together, until Kirito decided to tell Asuna about converting his account to Gun Gale Online.
- A Mob hunting squadron
- Dyne's squadron
- «H&K UMP»
- Mob hunting squadron players
- FN Minimi
- High-caliber laser rifle
- Optical blasters
- Boss monster in the ruins below SBC Glocken
- Plant monster in ALfheim Online
- Adapted from Volume 5, Chapter 3
- In the original novel, Sinon's PGM Ultima Ratio Hécate II was a boss drop, but in the anime, it was changed into a quest reward.
- The scene where Ginrou commented about the scenario if Sinon missed was not part of the original novel.
- In the original novel, Ginrou only used the nickname Sinocchi once, calling her Sinon in all other instances.
- In the novel, the Mob hunting squadron was only spotted twenty minutes after Ginrou attempted flirting with Sinon. In the anime, the squadron was spotted immediately after the scene.
- The ALO scenes were not part of the novel.
- In the anime, Kazuto did not tell Asuna about converting his avatar to GGO during their date, instead, he told her about it while in ALfheim Online.
- In Ginrou's point of view, both Miso and Arashi were written in all capital letters.
- While engaging Behemoth's squadron, Ginrou's HUD indicates his primary weapon is Sinon's Hecate, while in fact, he is equipped with a UMP.
- By the time Sinon decided to go up the tower, one of her party members who had taken the left wing was already killed. However, Sinon's HUD before the scene where she jumped out of the tower still showed that only Dyne and Ginrou were killed.
- The animation for Silica's first attack on the plant monster is similar to the animation for Kirito's last attack on Illfang the Kobold Lord in episode 2 of the first season.
- This was an MP7 sub-machine gun in the novel.