Remus's jealousy over Sirius and Mary intensifies as their relationship deepens, with the couple constantly kissing and making plans together. During a particularly difficult full moon approach, Remus snaps at Sirius for being late due to "snogging MacDonald," revealing his emotional turmoil. The successful Animagus transformation continues to work, giving Remus painless moons, but his internal struggle with his feelings for Sirius grows more challenging. As Mary faces increased danger from Slytherins for dating a pureblood, the political tensions of the wizarding war intersect with personal relationships in increasingly dangerous ways.

Sirius plans a grand sixteenth birthday party while continuing his relationship with Mary, leaving Remus to navigate his unrequited feelings. The party becomes a raucous celebration with stolen firewhisky, loud music, and dancing couples. Remus watches helplessly as Sirius and Mary grow closer, dancing to songs like "Wishin' and Hopin'" by Dusty Springfield. When Marlene offers to dance with him and jokes about helping him win the old snogging bet, Remus realizes how isolated he feels from his friends' romantic pursuits, leading to a bittersweet evening of celebration tinged with longing.

The marauders reveal their greatest secret to Remus on the full moon - they've become Animagi. James transforms into a majestic stag, Sirius becomes a large black dog, and Peter turns into a brown rat. Their years of secret study and practice culminate in this moment as they join Remus in the Shrieking Shack for his transformation. For the first time, the wolf has a pack, and Remus experiences a full moon without pain or self-harm. The chapter explores Remus's intense internal struggle with his sexuality and attraction to Sirius, while building to this pivotal moment of friendship and magical achievement.

Through letters between the marauders, we see Sirius struggling at home with mysterious family meetings while forced to remain under supervision. He stages small rebellions like putting up muggle girl posters, earning restrictions but maintaining his defiance. Meanwhile, Remus experiences his first summer romance with Grant Chapman, a charismatic sixteen-year-old who introduces him to his sexuality through stolen moments of kissing and intimacy. The relationship becomes a secret sanctuary for Remus, who realizes he's always been attracted to boys but keeps this revelation hidden from his Hogwarts friends.

During the Gryffindor vs Ravenclaw Quidditch match, a bludger meant for Sirius accidentally strikes his brother Regulus, knocking him unconscious in a terrifying fall. Sirius desperately tries to save him but arrives too late, though Madam Hooch slows Regulus's descent. The aftermath brings Walpurga Black to Hogwarts, where she coldly dismisses Sirius and takes Regulus home. Her cruel treatment of Sirius, calling him weak for showing emotion and denying him basic compassion, reveals the toxic dynamics of the Black family and deepens Sirius's trauma.

Remus reaches his tipping point during a troubled summer at St Edmund's. The marauders exchange concerned letters while Sirius faces mounting family tensions with mysterious meetings. Remus falls in with Ste's criminal gang, drinking, smoking, and fighting to cope with his rage about Greyback and his father's death. When the full moon arrives, he finally confronts his anger and decides to hunt down Greyback himself.

Remus returns to Hogwarts after a summer of successful burglaries with Craig Newman's gang, his trunk now filled with stolen cigarettes to sell. The marauders reunite on the Hogwarts Express, but tension arises when James, Sirius, and Peter hint at a secret plan they won't share with Remus. At the welcome feast, Dumbledore's ominous warnings about unity against darkness reflect growing concerns about dark magic and a mysterious Dark Lord that Sirius's family supports. Despite the unsettling political climate, the boys find comfort in being back at school together.

Summer letters reveal that Sirius escapes his arranged marriage when Narcissa makes an unbreakable vow to marry Lucius Malfoy instead, throwing the Black family into chaos. While his friends enjoy their holidays, Remus faces isolation at St. Edmund's but finds purpose in advancing his studies with help from Madam Pomfrey's improved care. Desperate to repay his friends' generosity and lacking any money, Remus makes a fateful decision when skinhead Craig Newman recruits him for a burglary, marking the beginning of his brief criminal career.

The Marauders spend their final day of second year causing chaos, unleashing a foam flood that engulfs the castle and sends students outdoors to enjoy the sunshine. Remus juggles returning library books, an end-of-year checkup with Madam Pomfrey, and helping Sirius pack while learning about Sirius’s potential betrothal and the fear he may be sent to Durmstrang.

As second-year exams approach, tensions rise among the Marauders and their classmates. Remus struggles to balance his studies with the secret of his transformations, while Sirius masks his worries with bravado. James pushes everyone to keep practicing, determined to outperform the Slytherins, and Peter tries desperately to keep up. The group faces mounting pressure, but their bond begins to deepen as they lean on one another through the chaos.