The narrative follows Marge, a seemingly ordinary member of the S-rank party "Silver Divine Sword," whose unique skill, "Skill Lend," allows him to lend his learned abilities to his companions. The party consists of Altra, a formidable swordsman with the unique skill "Sword Saint"; Elia, a talented mage with "Ancient Wisdom" and "High-Speed Chant"; Gordon, a defensive powerhouse with "Obsidian" and high mobility skills; and Tina, a healer with "Angel's White Wings" capable of resurrection. Marge's role is that of a skill provider, a "skill warehouse," as his own abilities are entirely lent out.
The chapters detail Marge's growing disillusionment with the party. He overhears Altra, Gordon, and Elia discussing his perceived lack of talent and the burden he represents, suggesting it's time for him to leave. This sentiment stems from an incident three years prior when Altra's reckless charge into an A-rank dungeon, despite Marge's lack of combat skills, succeeded due to luck, leading Altra to believe in his own infallibility and disregard Marge's input. Marge, acknowledging the talent gap, resolves to leave after the next dungeon, planning to return all his lent skills.
During their current expedition into the "Abyss of Coming Calamity," a dungeon notorious for its potent poisons, Marge is treated with disdain. He is forced to lie on the ground to avoid being hit by Altra's attacks and is kicked and berated for being slow or dirty. The party, however, relies heavily on Marge's lent skills, such as "Hawk Eye" for Altra and various poison resistance skills, to navigate the dangerous environment. Marge realizes that his contributions, though vital, are completely unacknowledged.
Upon reaching the boss room, a massive stone door adorned with a dragon relief, Altra reveals his true intentions. To avoid paying Marge his severance pay, as per guild regulations for seven years of service, Altra plans to have Marge be the first to enter the boss room, effectively sacrificing him. The other party members, while not actively participating in the decision, passively agree, citing it as a majority decision or leader's choice. Elia, however, expresses dissent, though ultimately succumbs to the majority.
Marge, understanding their motive, makes a final request: to have his skills returned. He explains that his skills, lent out for six years, have accumulated immense interest, calculated with a compound interest system that Elia, the intelligent mage, initially overlooked. The sheer volume of skill points, amplified by the compound interest, overwhelms the party members, causing them to collapse. Marge, now with his skills returned and significantly evolved, enters the boss room alone.
Inside, Marge confronts the boss, the "White Evil Dragon Vritra," a creature fated to be unkillable by conventional means. He uses his newly evolved skills, including "Spatial Leap" and "Asura's Six Arms," to evade Vritra's attacks. He then proceeds to seize Elia's unique skill, "Ancient Wisdom," which evolves into "Songs of the Divine Age," and uses it to learn a powerful ice magic. He freezes Vritra's regenerating body and uses "Spatial Leap" to send its frozen fragments into the void of space, effectively defeating it and causing the dungeon to collapse.
Marge discovers Vritra's egg and decides to raise it, believing it might be the only entity capable of stopping Vritra in the future. He then leaves the dungeon, collecting his share of the rewards and severance pay. He encounters "Koe," a mysterious entity residing within his consciousness, who has been observing him throughout his time with the party. Marge uses his healing skills to grant Koe a physical body.
The story concludes with Marge and Koe leaving the town, heading towards an unknown destination. Marge intends to raise Vritra's egg and teach Koe about the human world. The remaining unique skills of Altra and Gordon are still in Marge's possession, hinting at future confrontations. Meanwhile, Altra and the other party members awaken, disoriented and with fragmented memories, concocting a false narrative of Marge's betrayal to cover their own actions and the party's subsequent failure to retrieve the boss's body. Elia, however, shows signs of understanding the true implications of Marge's actions, particularly regarding the deliciousness of bread dipped in soup, a subtle nod to Marge's past simple pleasures.
