King of Sloth (2024), an adult contemporary romance by Ana Huang, is the fourth installment in the Kings of Sin series. The novel alternates between the dual first-person perspectives of Xavier Castillo, a wealthy but reluctant heir with a reputation as a party boy, and Sloane Castillo, his publicist, who is tasked with keeping his public image pristine. When Xavier learns that his father’s will is set to strip him of any rights to the family fortune if he fails to assume a CEO position by his 30th birthday, Xavier takes advantage of a loophole in the wording. With Sloane’s help, he reinvents his lazy image through hard work and dedication as he labors to establish a successful nightclub in order to fulfill the terms of his father’s will. However, the two do not expect to fall in love in the process.

This guide refers to the 2024 e-book edition published by Kindle Unlimited.

Content Warning: The source text and this guide discuss the deaths of loved ones and chronic illness.

Plot Summary

Xavier Castillo has earned a reputation as a charming yet seemingly unmotivated party boy who is kept in check by his overworked, high-strung publicist, Sloane Kensington. Despite the public personas that the two portray to the world, they both hide deep emotional wounds. Beneath Xavier’s carefree façade, he harbors deep guilt over his mother’s tragic death in a fire—which he blames himself for starting—and he also has a debilitating fear of failure. These unaddressed issues have driven his avoidance of adult responsibility. 

Sloane, on the other hand, is an emotionally guarded publicist whose ice-cold demeanor serves her well in her career but sabotages all her relationships. Because her ex-fiancé cheated on her with her more emotionally open sister, Georgia, the Kensington family now suffers from an irreparable rift, and Sloane no longer has contact with the only person she genuinely considers to be family—her younger half-sister, Penelope (“Pen”), who is kept under lock and key due to her struggles with chronic fatigue syndrome.

The novel starts with Sloane breaking into Xavier’s Greek villa and dragging him to a gala meant to honor his father as philanthropist of the year. Xavier only agrees to attend on the condition that Sloane agrees to take a one-week trip with him to Spain—a forced vacation that he believes she desperately needs. Sloane has only ever taken two days of vacation, and only when it involved a family death or a hospitalization, so she is very reluctant but eventually agrees. When she leaves the gala early to visit her sister Pen in secret, Xavier gets into media trouble by ditching the gala to party with his friends at a nearby nightclub.

Sloane must cut the night with Pen short in order to retrieve Xavier. Rather than returning to their hotel, Xavier arranges for them to fly to Spain immediately. Their first day includes a spa trip during which Sloane finds it difficult to relax. When they return to the villa that they share, Sloane is outraged to discover that Xavier’s friends have shown up in Spain and thrown a party. Xavier becomes jealous when Sloane seems acquainted with one of his friends, Luca Russo. Xavier comments on Sloane’s lack of dancing ability, calling her an “ice queen,” and she storms off.

The next day, Xavier wonders what he said that offended Sloane. He eventually apologizes for criticizing her dancing, and while Sloane was actually upset about the ice-queen comment, she does not correct his assumption. When Xavier discovers that Sloane has a hobby of watching and hate-reviewing rom-coms, he joins her in watching one. She is surprised to enjoy his company. Over the course of the trip, Sloane and Xavier become close. They have a few moments of romantic and sexual tension, but nothing explicit occurs. A gossip blogger, Perry Wilson, posts invasive blogs about their time in Spain, earning Sloane’s continued ire.

One day, Sloane receives a personal message that shocks her. It is from her father, to whom she hasn’t spoken in years, informing her of her sister’s pregnancy with Sloane’s ex-fiancé, Bentley. She then receives a work-related call that informs her that Xavier’s father’s ongoing battle with cancer has worsened his condition and that he might not last the night. After informing Xavier of the new development, they rush to Bogotà, Colombia, where Xavier must confront his estranged father.

Xavier’s father expresses disappointment in Xavier until his death. He pressures Xavier to take on the role as CEO of the Castillo Group, but Xavier is very resistant. Xavier’s father shares a letter written by Xavier’s late mother, which Xavier was meant to open on his 21st birthday—nearly nine years ago. The letter expresses her pride in him no matter what path he chooses in life. She encourages him to follow his passions. This inspires Xavier to turn to his old hobby of drawing bar blueprints.

When Xavier’s father dies, the family is left with a controversial will. Xavier will inherit the majority—$7.9 billion in fixed and liquid assets—only if he meets certain conditions. He must assume the role of CEO by his 30th birthday (in six months) and serve for at least five consecutive years, during which time the company must remain profitable. A committee will evaluate his performance every six months, determining whether or not he meets the required standards. Failure to meet these terms will result in the entire inheritance going to charity. Sloane is among the five people chosen to be on the committee. Through careful examination of the wording, it is clear that his father left a loophole—Xavier must be a CEO, but the will does not explicitly state what company he must be CEO of. Xavier becomes motivated to pursue a business venture that brings him passion and excitement: opening a nightclub.

With the help of Sloane, her acquaintance Kai Young, and a list of high-profile contacts, Xavier works hard to make his vision a reality. Meanwhile, he and Sloane become closer. Their professional relationship morphs into a more romantic one. Eventually, at Xavier’s insistence, Sloane agrees to a two-month trial period in which they attempt to date. If they decide that they fit well together by the end of December, then they will pursue a long-term relationship.

As she dates Xavier, Sloane’s faith in romance begins to blossom again. Her hatred for rom-coms lessens, and she finds herself enjoying clichéd displays of affection. Meanwhile, Xavier secures business partners and premises for his nightclub, and other influential members of society help him with security, menus, permits, and licensing.

When Sloane’s sister Pen has an accident and is hospitalized, Sloane risks further fallout with her family by visiting Pen. Her father and stepmother, George and Caroline, and her sister Georgia are not happy to see her. With Xavier by her side, Sloane has a hostile confrontation with them, and the incident illustrates the irreparable rift between her and her family members. Xavier learns that Georgia’s husband, Bentley, is Sloane’s ex-husband; Bentley cheated on Sloane with Georgia five years ago, and rather than showing remorse, the couple blamed their behavior on Sloane’s lack of emotional capacity. Sloane cut ties with her family.

When Pen recovers, Xavier works with Rhea (Pen’s nanny) to set up a surprise secret hangout where Sloane and Pen can meet without interference from George and Caroline. Unfortunately, gossip blogger Perry Wilson finds out and publishes this information on his blog. As a result, Rhea is fired, and the parental security around Pen increases, making it impossible for Sloane to see her sister. While Xavier feels guilty, believing that it’s his fault, Sloane only becomes more motivated to take Perry down professionally. She enlists the help of her friends to spread false gossip, which Perry publishes without fact-checking it first. The involved celebrities sue Perry for libel, causing him significant financial hardship that he can only escape by selling his blog to Kai Young, who transforms it into a reputable publication. 

Meanwhile, as the opening day looms nearer, Xavier rushes to get his club ready. When faulty wiring is brought to his attention but there is no time to fix it before opening, he delays the fix until after. However, soon there is a fire in the nightclub, which threatens the lives of Xavier and others. Though everyone survives, Xavier believes that it was almost a repeat of his past—the fire he started that caused the death of his mother. Xavier is determined to quit and even lashes out at Sloane when she tries to convince him otherwise, straining their relationship.

After learning that someone sabotaged his nightclub, Xavier is relieved to realize that the fire wasn’t his fault, and he resumes his work and attempts to reconcile with Sloane. Afraid of getting hurt as she has in the past, Sloane ends their relationship prematurely, but Xavier doesn’t want to accept this. He asks her to meet him on the roof of the Empire State Building at midnight on the day their trial period ends if she wishes to pursue a long-term relationship with him. On the fateful day, Sloane decides at the last minute that she is in love with Xavier and wants to be with him. She races to the Empire State Building, and they share a passionate, clichéd recoupling.

Eventually, Sloane is approached by Caroline and George. Pen has been inconsolable, and the only way to placate her is to allow her to see Sloane once a week and rehire Rhea. Sloane is thrilled with this new development. Xavier has a successful club opening, and three fifths of his committee vote “yes” to him fulfilling the terms of his father’s will for the first six months, ensuring that a portion of the inheritance will go to him. In the following 18 months, Xavier’s nightclub becomes famous, and he passes three more evaluations. Xavier and Sloane move in together and take a one-month-long vacation to Spain.