Wheeler Arc

The Wheeler Arc runs from chapter 79 to chapter 89 in volumes 12 and 13, with its anime adaptation beginning in the back half of episode 47 of season 3. Positioned between the Bus Hijacking Arc and the Term Finals Arc, it pits WISE against Winston Wheeler, a gifted turncoat from Westalis Intelligence's communications division whose stolen documents include a coded map of operations in Ostania, Operation Strix among them.

A comedic prologue sets the stakes at home. Drunk at a work mixer, Yor invents complaints about Loid to fit in with her griping coworkers, and her clumsy attempt to repeat the act sober convinces Loid she is dissatisfied with their life together. The misunderstanding is still hanging when Fiona reports the theft, and both intelligence services race to Shellbury in northwestern Ostania, where Wheeler plans to hand the files to the SSS.

Loid rejects Fiona's proposal to scrap every Ostanian operation and start clean, unwilling to lose years of progress toward Donovan Desmond. Disguised as Wheeler, he stalls the SSS contingent, but a deliberately mismatched detail about a gemstone tiepin exposes both him and Jeffrey, the SSS officer secretly feeding WISE information. Fleeing through rigged traps into the sewers, Loid collides with the real Yuri, and the two fight without recognizing each other, gunfire giving way to fists. Loid wins, hesitates twice over the killing blow, and spares him after hearing Yuri unconsciously apologize to Yor. Above ground, Fiona flushes Wheeler out by staging a car accident and reading the onlookers, loses him when he takes an agent hostage, then corners him in the tunnels, where he has already beaten the disguised Loid and nearly unmasked him. Wheeler taunts that her attachment to Twilight caps her potential; her answering fury shatters her own arm and leg but batters him into submission, and the agents haul him out of Shellbury in custody.

The homecomings carry the fallout. Yor cheerfully admits her gripes were fabricated, dropping Loid to the floor in relief, but Yuri barges in hunting for the arm wound he gave Twilight, and though Loid's disguise work passes the sleeve check, a seed of suspicion takes root. Sylvia, covering hospital shifts while Fiona recuperates, gently signals that she knows exactly whom Fiona's recklessness was for. Lighter chapters follow Damian's fumbling gift of cakes to Anya, procured by his mother Melinda with a note hoping the two grow closer, and Yuri's crisis of confidence, which ends with a slap and a lecture from his colleague Chloe about what his death would do to Yor.

Both agencies now know they harbor leaks, and Wheeler himself sits in WISE custody. The deeper consequences are personal: Yuri and Twilight have crossed paths professionally for the first time, and Yuri begins entertaining the unthinkable idea that Loid Forger could be the spy he hunts. Loid catches himself hesitating over Yor's brother and questioning his own feelings toward her, while Sylvia's knowing words leave Fiona's devotion an open secret within WISE. The arc also introduces Chloe, Yuri's fellow officer and collegemate.