Heartless Sky (2021) is a dark romantasy novel by British authors Caroline Peckham and Susanne Valenti. It is the seventh installment in their bestselling Zodiac Academy series, which has gained significant popularity on social media. Peckham and Valenti are sisters and prolific authors known for their interconnected dark romance and fantasy worlds. The Zodiac Academy series is a USA Today and Wall Street Journal bestseller and part of the larger World of Solaria, which includes the prequel series Ruthless Boys of the Zodiac and the spinoff Darkmore Penitentiary.

Heartless Sky continues the story of twin Fae princesses Darcy and Tory Vega. As they and their allies prepare for war against the tyrannical King Lionel Acrux, they must contend with a mysterious murderer within their ranks, a web of ancient prophecies, and the immense power and responsibilities of their lineage. The novel explores themes such as The Value of Love Despite Uncertainty, The Danger of Secrets, Sacrifice as Expression of Love & Loyalty. 

This guide is based on the 2021 Caroline Peckham & Susanne Valenti e-book edition.

Content Warning: The source material and this guide contain depictions of bullying, graphic violence, sexual content, cursing, illness or death, suicide, physical abuse, and emotional abuse.

Plot Summary

The Zodiac Academy series is set in the fantasy world of Solaria, which is populated by Fae (magical creatures); Fae possess a variety of magical powers, which are largely determined by the Order to which they belong (Orders include Vampires, Werewolves, Phoenixes, and more). Heartless Sky begins immediately after a large-scale battle that took place on Christmas Day. The battle involved a confrontation between forces loyal to Tory and Darcy Vega (twin sisters who are the rightful heirs to the throne of Solaria) and the forces of Lionel Acrux (a powerful Fae who has usurped the throne and holds it through a combination of political machinations and dark magic). 

While the battle raged, Darius Acrux (Lionel’s eldest son, who is in a romantic relationship with Tory) was absent; he secretly brokered a deal with fate in which he agreed to die within one year in exchange for Tory and Darcy safely escaping the battle. Darius’s bargain also had other magical implications: It lifted a curse that had previously kept he and Tory apart and severed an existing “guardian bond” between he and Lance Orion (Darcy’s lover and another staunch ally to the twins). When Tory, Darcy, Orion, and their allies flee from the scene of the battle to avoid annihilation, they notice evidence of these changes, but none are aware of Darius’s bargain. Darcy is also worried because Lionel’s ally Lavinia (an ancient spirit who possesses powerful dark magic) seems to have cursed her. 

Darcy and Tory find sanctuary at The Burrows, a stronghold for the rebel movement (many Fae reject Lionel’s authority). Along with Darius and Orion, they have support from the Celestial Heirs (a group of young men who were previously being groomed to collectively ascend the throne but who now support the twins), their half-brother Gabriel (who is a powerful Seer), their loyal friend Geraldine, and Darius’s younger brother Xavier. 

The Heirs comprise Caleb, Max, and Seth; Darius is the fourth Heir. All these individuals assemble at the Burrows; they will be arrested and killed if Lionel or his forces apprehend them. Darius joins them but does not disclose the truth about his bargain with fate. 

Darius and Tory reach a new stage of trust and intimacy in their romantic relationship, although Darius is tortured by the knowledge that their time together is fleeting. Darcy and Orion (whose relationship fragmented after Orion was imprisoned for allegedly coercing and seducing Darcy, his former student) also reconcile, becoming closer than ever. However, the fragile peace is soon shattered by a series of gruesome murders within The Burrows, sowing paranoia among the rebels.

While the twins and their allies search for the killer, they also try to understand how to unseat and destroy Lionel. Orion discovers a prophecy revealing that twelve magical gemstones must be found to restore the twins to their throne. He locates six and begins researching how to find the others. The twins learn that their parents (King Hail Vega and Queen Merissa Vega) were killed by a Nymph named Alejandro on Lionel’s orders. Nymphs are magical creatures who are traditionally enemies to the Fae, although Lionel has successfully manipulated a vast Nymph army into obeying him and helping him maintain power. Meanwhile, Lionel is more determined than ever to get revenge upon the rebels and eliminate the twins. He is furious that both his sons (Darius and Xavier) are working against him, and he agrees to marry Lavinia, hoping they will produce a new heir together. 

The twins and their allies learn that Lavinia is drawing power from rituals involving a “rift” (magical portals) that provide her with access to forces of dark magic. They realize that closing the rifts is the key to weakening her and Lionel. During a dangerous mission to an isolated temple site, the twins and their allies successfully close the rift. However, Tory encounters a vision that leads her to believe there are other rifts in Solaria. The twins and their allies begin working to obtain magical implements that will allow them to locate and close these rifts. Meanwhile, Tory and Darcy begin using their combined magic to gradually eradicate the curse that Lavinia placed on Tory. Orion locates one more gemstone, bringing him closer to possessing the full set. 

Drawing on forces of dark magic, Lavinia gives birth to a strange, monstrous heir. During a mission to steal a magical eye from Lionel’s accomplice, Vard (the eye is needed to locate the rifts), the Heirs kill this new heir, which they believe is simply a monstrous creature. Lionel is secretly relieved, since he is growing increasingly frightened of Lavinia and he plans to pursue fathering a new heir with someone else instead. Using the magical implements, the twins and their allies close all the remaining rifts, significantly weakening Lionel and Lavinia’s power. It is now time for a final attack on Lionel and Darius reveals the truth about his bargain and impending death. 

Tory is devastated and makes Darius swear to resist his fate. The two of them marry. Before they can attack Lionel, Darius and the other Heirs learn that their parents and younger siblings are being held captive on Lionel’s estate. Darius, Caleb, Seth, and Max rush to help their families; once they are gone, Lavinia and Lionel launch an attack on the Burrows, accompanied by a huge Nymph army. Darius returns to protect Xavier while the other three Heirs try to help their families. However, Caleb, Seth, and Max all end up being captured by Lionel’s forces. Meanwhile, Darius is killed by Lionel. 

As the battle rages, Lavinia triggers the full force of Tory’s curse, prompting her to transform into a monstrous beast and begin killing the Fae who are fighting for her cause. Tory realizes with horror that she has periodically been transforming into the beast and killing loyal Fae: She is the murderer everyone has been seeking. Orion helps Tory to temporarily regain control, but she realizes that her magic is gone and she is now mortal. Horrified by what she has done, and fearing she will return to her beast form, she flees to the mountains. Orion confronts Lavinia and strikes a deal: He will trade his body to Lavinia and remain completely under her power for three moon cycles. At the end of that time, Lavinia will have to lift Tory’s curse. Lavinia takes Orion captive as the battle rages on.

Tory succeeds in killing Alejandro (the Nymph who killed her parents) but calls for the rebel forces to retreat, as they are suffering devastating losses. When she finds Darius’s body, she is overwhelmed with grief. Meanwhile, to protect Tory, Gabriel has allowed himself to be taken prisoner. Tory receives one cryptic prophecy from him but it is unclear what future is being foretold. At the end of the novel, the rebel army is shattered. Darius is dead, Orion is bound to Lavinia, Gabriel, Max, Seth, and Caleb have all been captured, and Darcy has fled to avoid harming anyone else due to the destructive curse. Tory is left to face the seemingly impossible task of winning a war that appears all but lost.