Meliodas, Hawk and Elizabeth's journey led them to the Forest of White Dreams, where they have come searching for one of the Seven Deadly Sins. There, the Prankster Imps, who were being threatened by the Serpent's Sin of Envy, Diane to not let any Holy Knights come through, tried to stop the three, thinking they were Holy Knights. However, Meliodas manages to trick, and thus defeat them, and even accidently lead them to Diane. Having reunited with Diane, Meliodas discusses about the event that led them to be labelled as criminals ten years ago, since he didn't have any memories of that day. Just then, Gilthunder arrives and binds everyone with his lighting magic.
Gilthunder, pointing his sword at Meliodas' neck and saying that he wants to avenge his father, and also wants to prove he has surpassed him, declares that he is stronger than any of the Deadly Sins, and says that he will unbind him and Diane to fight them. Before he could do so, however, both easily break his spell themselves, with Meliodas instructing Diane not to interfere in their battle. Gilthunder then attacks first using a powerful lighting bolt. The Sin of Wrath easily repels the spell back at Gilthunder, but the latter dodges the attack and gets behind the former, slashing him from behind and causing him to fall to the ground.
Gilthunder question Meliodas for last words, and Meliodas, seemingly in his last moments, Meliodas asks for the whereabouts of the other five members of the Seven Deadly Sins. Gilthunder answers, telling him that while the whereabouts of three of them remain unknown, it is known that the Fox's Sin of Greed is imprisoned in the Baste Dungeon and the Grizzly's Sin of Sloth has perished in the Capital of the Dead. Hearing that, Meliodas quickly jumps back up, leading Gilthunder to realize that Meliodas let himself be injured in order to obtain information about the other Deadly Sins. Meliodas, though not wanting to fight anymore, dodges all of Gilthunder's attacks. The Holy Knight eventually gets behind Meliodas and points his sword towards his neck. Suddenly, Diane interrupts the battle and lifts him with a hand. He unsuccessfully attempts to escape her grasp by discharging lightning, and Diane throws from the forest to a neighboring village.
Gilthunder is seen falling down from the sky into a church in a neighboring village. He walks out unscathed from the remnants of the collapsed church, whilst the wounded priests and civilians cry for help. After learning the location of two of the Deadly Sins, the group decides to go find the Sin of Greed, Ban, who was imprisoned in the Baste Dungeon.