The Dark Hero's Story is a CD drama story of the Overlord series. It was released on January 31, 2014 alongside Overlord Volume 06.
SIDE STORY 1: Ainz is in his inn room, counting how much money he has to give to his subordinates. Upon finishing what he did, Nabe walks in after completing Ainz's earlier commands from before. He then sends Nabe out on another errand again that seems to be related with the usage of Exchange Box. In addition, he reminds her to be careful of unknown threats that may have harmed Shalltear the same way.
In another part of E-Rantel, two men by the name of Andre and Torkel Karan Dale Völkchenheim are wandering through the streets, looking for an inn to stay in. This was until they came across Nabe which Torkel fell in love with her at first sight. It was during that same time however, he thought of making her his wife in the face of a baffled Andre. Already losing sight of Nabe, the two men rush after her. The love-struck man proposes to her with marriage, but she quickly rejects him moments later.
Afterwards, Andre began to look for information about her, learning that she was actually part of an Adamantite adventurer group known as "Darkness." Eventually, these two men would later begin to set up a quest and request aid from the team so he could learn more about Nabe, with Torkel attempting to hatch up a plan in order to get himself and Nabe together as a couple. However, Andre easily dismisses that idea due to Nabe's famous reputation as an adamantite adventurer and the other partner working beside her being Momon, the Dark Hero. Upon learning this, Torkel became frustrated and is left in agony while screaming in disbelief, believing that Momon is not worthy of Nabe's love.
Yet Andre has also warned Torkel to tone his voice down whenever he slanders Momon so he does not upset the people of E-Rantel. This was due to the sphere of influence "Darkness" has in this city as an adamantite adventurer group and it may carry backlash against those who lashes out at him. Torkel later asks what kind of person Momon was which Andre responds, describing his full appearance to be a warrior clad in black. He tells Torkel of Momon's feats such as completing quests quickly or riding a fearsome monster. Andre sees his personality to be caring as shown when he would spend time with the people around him, but also help them when they're injured. His compassionate actions lead Andre to accept that Momon is what defines a "hero".
Nevertheless, Andre tells Torkel that he wasn't able to clearly distinguish the relationship between Momon and Nabe. He only hears baseless rumors about these two adventurers as being in the position of master and servant or even lovers. However, Andre concluded to Torkel that Nabe tends to always stay by Momon's side and following him faithfully. Although to Torkel's surprise, he refuses to give up and wanted to confront them on whether they're lovers or not. He sees this as an opportunity of a lifetime for him to confess his love to Nabe even if knowing he will be rejected the second time.
Witnessing Torkel's resolve, Andre was in awe and more than ready to support him with his goal by spending all of their money to hire "Darkness". While Torkel was shocked by his compliance, Andre believes that this would be a good learning experience to help him to rule in the future. Such experience is observing the strength of "Darkness" in action as an adamantite adventurer group. On the other hand, vowing to Torkel that they will no longer spend freely in E-Rantel anymore as part of their exchange.
The next day, Torkel and Andre are waiting for Darkness to arrive so that they can begin their mission. Torkel immediately starts antagonizing Momon and praising Nabe as soon as they meet up. Andre does all that he can so that the situation doesn't escalate. Momon notices this and does what he can to prevent Nabe from attacking Torkel.
The four of them set off, Torkel and Andre on a horse each, and Momon and Nabe sharing a golem horse. After a while they take a rest, which Torkel takes as an opportunity to be alone with Nabe. He professes his love for her and asks for her hand in marriage. She bluntly refuses his confession and calls him weak.
Torkel asks if she follows Momon because he is so strong, to which she replied no. She says that he's different and that she would follow Momon regardless on any circumstance. Torkel realizes that Nabe was willing to do anything for Momon and accepted her decision. The two then returned to Andre and Momon to continue their journey.
A little later on, Momon hears something, causing all of them to travel to the source of the sound. They encountered a Gigant Basilisk in a nearby village hunting goblins. Despite Torkel's warnings to Momon that the Gigant Basilisk would be too powerful and dangerous to fight, it was easily defeated by him. In the future, Torkel's story of his encounter with Dark Hero Momon whose heroic battle against the Gigant Basilisk are retold by Torkel himself to his descendants later on in his life.
Ainz returns to Nazarick and asks Yuri what the Guardians and Pleiades want as compensation. He learns what they want and thinks of a way to get it. (Explained in Story 2)
SIDE STORY 2: Albedo holds a meeting for all the Floor Guardians, minus Victim and Gargantua. The Overseer Guardians explains that her gathering her peers was directly from Ainz Ooal Gown himself. The Guardians are enthusiastic to hear what new orders they are about to receive and eagerly await Albedo's response. As she relays Ainz's message, he plans to implement a salary and compensation based system for all the NPCs, and wishes them to provide a list of their desires. Ainz's message causes the Guardians to become stumped as they cannot think of anything else they could want as serving their master is the most fulfilling reward. Albedo is troubled as they cannot complete their tasks without something to provide Ainz with, so she urges them to think.
To start off she suggests clothes, though Shalltear rebukes this, stating her master Peroroncino provided her with an assortment of clothing. Albedo on the other hands wishes to procure some new dresses as she only has dresses of the same design. Demiurge seconds the idea, as he wishes to have some other suits to try. Cocytus states he does not need any clothes, which Aura comments because he is nude, embarrassing the 5th Floor Guardian.
Finally having an item, Albedo adds it to the list, though she wonders if the New World has any clothing that can impress them. Aura brushes it off and states that they should let the people working outside Nazarick to lead the investigations. Solution Epsilon and Lupusregina Beta are candidates to help find women's clothing and Demiurge suggests they can ask Ainz for men's clothes.
Shalltear suggests that they ask for humans so as to use them as toys. Demiurge agrees stating some of their comrades might want to eat them or feed them to their familiars. Adding the item to the list, Albedo asks for more suggestions, to which Aura answers that she wants Rororo. Cocytus immediately rejects the proposition as Rororo is a pet hydra of the lizardmen and hence under his jurisdiction. Aura then settles for having Rororo's children for her beast collection to which Cocytus will have to consider it.
Cocytus's request is for new weapons, not to use but to add to his collection even if they are inferior to the ones he possesses. It was only until when Shalltear requests a coupon to sleep with Ainz, does Albedo lose herself in the ecstasy of the thought of spending a night in bed with her master. Cocytus wonders if something like that can be put a price on and is concern that it will distress Ainz. Aura believes that if they put a price on it is will be rude to Ainz. Demiurge suggests that everyone suggest a price in the form of an auction for the coupon. He recommends they do the auction twice for clarity.
They have Yuri Alpha host the auction, and each Guardian has an assigned salary of 15 million.