Carl’s Doomsday Scenario follows Carl, Princess Donut, and Mongo through the third floor of Dungeon Crawler World. The floor begins with permanent race and class choices, then places them in the Over City, a network of inhabited settlements separated by dangerous ruins. Their first major quest entangles them in the conflict between Signet and Grimaldi’s circus. A later investigation into murdered women exposes a conspiracy within a skyfowl town. Stopping it produces the threatened catastrophe that gives the book its name. The account below includes the novel’s ending and epilogue.
Arrival and the choices that shape the floor
Carl, Donut, Mongo, and Mordecai arrive on the third floor from the green room. The golden arrival corridor seems to open onto a night sky, but Carl discovers that the apparent outdoors is a ceiling illusion. Before entering the city, the crawlers must make their selections. Donut takes the Former Child Actor class. It grants her poison and disease immunity and the Cockroach survival skill, which later prevents her death during the circus quest. Its Manager benefit also binds Mordecai to her: he will appear in the saferooms she uses instead of taking the magic-guild position he expected. Donut and Carl have followed advice from Odette without telling him, creating a breach of trust at the start of the new arrangement.
Carl chooses Primal as his race and Compensated Anarchist as his class. The Primal choice preserves his outward appearance and opens higher skill tiers, though it reduces his base attributes. Compensated Anarchist strengthens the unarmed fighting, explosives, and trap work he has already begun, while imposing penalties on conventional blades and damaging magic. Mordecai presents him to the floor under both new designations. The choices matter immediately: the third floor tests Carl’s willingness to use explosives and improvised tactics, while Donut’s new protection becomes decisive when she is incapacitated.
Mordecai leads them through a settlement of the Over City. He explains that entry points are randomized, so the people who descended near one another need not arrive together. Villages contain inns, guilds, shops, and guards; the surrounding urban ruins contain hostile creatures. The guards protect settlements by day, and Mordecai warns Carl and Donut against attacking residents or relying on the guards after dark. This arrangement gives the pair places to recover and train, but travel and quests repeatedly draw them beyond the gates.
The ruins and Grimaldi’s circus
The first trip into the ruins brings an attack by former circus lemurs. Carl and Donut encounter a quest connected to Grimaldi’s Traveling Circus, then retreat to a saferoom. Mordecai, newly subject to the manager arrangement, is already drunk when they find him there. The episode forces Carl and Donut to handle the immediate danger without the dependable direction they expected. Mongo also begins growing quickly as he fights and trains. Donut’s care for him is part of the party’s changing balance: after Carl refers to her as a pet, he acknowledges her as his partner when they decide to investigate the circus.
Near the circus they find signs that Tsarina Signet, a tattoo-covered summoner, has been branded a traitor. She confronts them outside its grounds and calls on them to hold off mold lions while she forms her battle squad. The lions descend from circus animals transformed by parasitic growth. Carl and Donut survive the clash, but Signet remains powerful enough to dictate terms. She seeks Grimaldi, the man she loved, now bound to the corrupted circus and its vine. Their encounter turns a monster-hunting quest into a dispute involving people who remember a life before the floor’s present horrors.
Signet later incapacitates Donut and brings Carl to Heather, a transformed roller-skating bear that has become a neighborhood boss. She needs Heather’s blood for a stronger summoning and makes Carl fight the bear while Donut cannot help him. Carl’s victory supplies the sacrifice Signet requires. Donut’s Cockroach skill later proves crucial while she remains exposed to danger; Mongo defends her from creatures that reach the building where she lies. Carl must return from the circus to protect them, and the three spend the rest of the night together until Donut wakes.
With a ticket granting passage through the circus’s public areas, Carl enters its big top. There he discovers that the growth connected to Grimaldi is a city boss. A direct fight would put him against both the vine and a setting designed for a larger group. Mordecai’s explanation of the vine gives Carl another method: blood from a poisoned person can break its connection with its symbionts. Carl poisons himself, lets the vine take his blood, and uses an antidote. He also contacts Zev about the program built around Signet’s revenge. His bargaining reflects his understanding that the producers want a dramatic confrontation as much as they want the quest to proceed. Carl then deliberately accepts the circus parasites while protecting his mind with Wisp Armor. Their connection lets him convey Grimaldi’s thoughts to Signet and argue that their efforts to protect the circus have turned them against each other. Grimaldi releases Signet from banishment; she enters the tent, and Carl cures his infestation. The quest completes without Carl killing the city boss. Zev’s remark about two simultaneous dramas alerts him to Donut’s peril elsewhere.
A town mystery replaces the circus quest
After the circus, Carl and Donut recover, sort their rewards, and explore more of the settlement. A large casino chip among Carl’s prizes can be played only at the Desperado Club’s casino. Mordecai takes them to the club, where they see its public nightlife and the Silk Road market. These places establish that the towns are more than staging areas for combat: former crawlers, merchants, performers, and local residents have lives within the dungeon’s economy. Mordecai’s conversations there also show how his manager role keeps him tied to Donut’s progress.
At an inn, an orc named GumGum asks for help. Mordecai wants to avoid another quest, but GumGum later shows Carl and Donut a pile of women’s bodies collected from the town. The dead women are not local, and new bodies appear in the streets each morning, many drained of blood. Carl and Donut accept a quest to learn why. GumGum is killed before they solve it. Donut insists that they continue, turning the inquiry from a reward opportunity into a commitment to the woman who first tried to expose the deaths.
GumGum’s belongings include a gate pass issued in Magistrate Featherfall’s name and a mysterious letter. Mordecai recognizes the letter’s writing as necroscript, although he cannot read it. Carl and Donut take their suspicions to Featherfall’s offices. His assistant, Miss Quill, blocks access to him. They use a corpse from the investigation to press their demand, and Carl takes advantage of Quill’s distraction with her collection of small figures to inspect the locked route to the magistrate. The visit does not establish Featherfall’s guilt. It does, however, give Carl a way to return to the building and plant explosives while the murder quest remains unresolved.
A broadcast appearance interrupts the investigation. On a panel with other guests, Carl and Donut meet Hekla, leader of Brynhild’s Daughters. Hekla asks them to help Katia Grim, an isolated member of her team who has fallen behind in levels. Donut agrees, and Katia reaches their town. Her Monster Truck Driver class gives her a durable, fast-moving body, but she is inexperienced and initially struggles to control its appearance. Carl and Donut bring her into the party to help her gain experience. The promise to Hekla becomes an immediate responsibility when Carl’s plan against the town’s apparent authorities puts Katia in the same danger as everyone nearby.
The investigation also leads Carl and Donut to city elves operating from a corrupt temple. Their account links GumGum’s questioning to the group’s violence, and the confrontation spills into the street near a family of dwarves. Mongo kills young Ricky Joe’s pet salamander, and Ricky Joe loses an arm in the ensuing fight. Carl heals the child’s immediate injuries but cannot restore the limb. The incident gives the town mystery a cost beyond the quest’s named victims: Carl and Donut’s intervention saves people from the elves while harming a child who had no part in their scheme.
The magistrate’s building and Quill’s plan
Carl detonates the explosives planted near Miss Quill’s office. The blast destroys much of the magistrate’s building, and the system credits the party with deaths there. Yet the murder quest remains open. Carl realizes that killing Featherfall and Quill has not supplied the missing explanation. In the wreckage, they find women suspended in a hidden room, some dead and others transformed into krasue. Burgundy, a survivor of the blast, explains that she is human by day and one of the creatures by night. She directs them toward Remex, a former magistrate kept in a nearby warehouse. Donut ends Burgundy’s suffering at her request as the building collapses around them.
Remex is neither the powerful lich nor the final boss Carl had expected. The system identifies him as a Soul Leech Capacitor and a bereft minion of Miss Quill. His account reverses the party’s earlier assumptions. Featherfall had sought greater control of the town’s animated swordsmen. After Remex’s death, Featherfall and Quill used a spell to summon him back as a source of power. Feedback killed Featherfall; Quill concealed his death and effectively ruled in his place. She controlled Remex and drew on the soul energy gathered by a crystal associated with the guards. The missing women were brought to her operation by manipulated city elves. Some became controllable krasue; others died during the transformation.
Quill’s aim extended beyond the town. According to Remex, she was completing an inherited, multi-generation spell called the Final War. Its final stage would unleash creatures across the Over City while sparing only the skyfowl and their families marked for protection. She had already begun the casting. Remex’s explanation completes the quest about the murdered women, but it also reveals the danger created by Quill’s death. The unfinished spell and accumulated power remain active without her to manage them.
The system announces a new group event for crawlers inside the threatened area. Katia is named among its hosts alongside Carl and Donut and cannot simply withdraw to safety. Carl tries to contain the overloaded soul crystal in a protective Sheol Glass case taken from Quill’s collection. The crystal detonates inside it. Once the first explosion has happened, he can pull the burning case into his inventory, preventing that blast from destroying the surrounding area. The resulting unstable explosive is identified as Carl’s Doomsday Scenario. It is a consequence of his improvised containment, not a device he carried into the floor.
The danger does not end there. Remex becomes the focus of a second, magical detonation preceded by pulses that interfere with crawlers’ equipment. Mordecai tells them to remove magical gear, and Carl sends warnings through the event’s group chat. With the Desperado Club route closed to them, the party and other crawlers run for a stairwell to the fourth floor. The pulses injure members of the fleeing group and force Donut to remove her Sepsis Crown. Katia reaches the stairs with them. They descend before the normal collapse of the third floor, leaving the impending blast behind.
Departure and immediate aftermath
The epilogue places Carl, Donut, Mongo, and Katia in Odette’s green room and on her show after the descent. Their arrival confirms that Katia has crossed the floor boundary with them. Odette’s interview returns the pair to the audience economy that influenced the circus confrontation: their actions have become entertainment, and their growing visibility attracts further attention. The displayed crawler leaderboard includes Carl and Donut, but its listed sums are bounties paid to other crawlers for killing them. The third floor has therefore changed more than their character builds. It has bound Mordecai to Donut, added Katia to their immediate circle, and carried the consequences of their public actions into the next floor.