Immortal

Immortal (2025) by Sue Lynn Tan is a standalone novel set in the same world as the Celestial Kingdom Duology. The novel follows Liyen, the heir to Tianxia. The God of War and an immortal queen seek Liyen because she harbors a Divine Pearl Lotus flower capable of healing all ailments. As Liyen becomes entangled with the God of War, she uncovers repressed memories from an unexpected past and an insidious war plot that threatens her kingdom and the lives of her loved ones. Tan is the author of Daughter of the Moon Goddess, Heart of the Sun Warrior, and Tales of the Celestial Kingdom. Her books have been translated into 16 languages and are USA Today and Sunday Times bestsellers. Tan was born in Malaysia and has lived in London, France, and Hong Kong.

This guide refers to the hardback edition published by Harper Voyager in 2025.

Content Warning: The source material and guide feature depictions of death.

Plot Summary

As heir to the mortal kingdom of Tianxia, Liyen was raised to ascend to the throne and continue serving the immortals who protected mortals from the Wuxin during the initial war between races. However, Liyen has a past she has long forgotten: She is the daughter of the immortal Queen Caihong. During the war, the Wuxin cast a powerful curse over her and her beloved, the God of War, Lord Zhangwei. The curse would have killed her if she did not become mortal and take the only cure in existence: the enchanted Divine Pearl Lotus flower. To become mortal, Liyen had to relinquish her memories. Then she became heir of Tianxia, where her surrogate grandfather raised her, and her Aunt Shou looked after her. Liyen quickly became friends with Aunt Shou’s adopted son, Chengyin.

When the Wuxin poison Liyen’s grandfather with the fatal waters of the Wangchuan River, he gives Liyen the Divine Pearl Lotus, a gift meant for the immortal queen, to save her life. He passes shortly after, leaving Liyen to ascend the throne.

When she is summoned to the Immortal Realm to gain Queen Caihong’s blessing, Liyen falls in love with the God of War, Lord Zhangwei. When she learns he is slowly dying from an injury sustained by a Wuxin attack during the war and needs her to freely give the lotus to save him, Liyen believes he feigned his feelings for her and flees. Lord Zhangwei follows her to the Mortal Realm to earn her trust back. Eventually, he brings her to the Kunlun Mountains, where the immortal Ancient Grandmaster resides, and the Tree of Everlasting Life blesses her. When an unprecedented Wuxin attack threatens their lives, Liyen notices Zhangwei’s waning strength and gifts him the lotus to restore his former power.

However, Liyen is separated from Zhangwei in the attack. The ruler of the Wuxin, Lord Dalian, takes her to the Netherworld, where he is revealed to be Aunt Shou’s biological son. Despite feeling hurt and betrayed by Aunt Shou, who turns out to be Wuxin, Liyen finds an ally in her as Aunt Shou demonstrates her continuing concern for Liyen’s well-being. Liyen learns that the waters of the Wangchuan River are weakening and the Wuxin need passage to the Mortal Realm to survive. This requires opening the gateway locked by the immortals to keep the Wuxin trapped in the Netherworld. Liyen is brought to the Temple of the Crimson Moon, where the Mirror of Destiny greets her and reveals her hidden past, including the Wuxin plot to curse and poison her.

Before the Tree of Everlasting Life blessed her, Liyen would have naturally become Wuxin due to the curse they placed on her when she was first poisoned. However, because she received the blessing, she has a choice: become Wuxin or return to being an immortal. After the mirror gives her visions of each future path, both of which end in suffering and death for all peoples, Liyen chooses neither, instead deciding to forge her own destiny.

With the memories of her past unlocked, Liyen treads carefully in the Wuxin homeland, biding her time while plotting to escape the realm. With the help of Zhangwei, who secretly infiltrates the Wuxin realm, Liyen learns that Dalian plans to take his armies into the Mortal Realm for greedy conquest. She thwarts Dalian’s plot to open the gateway, and the ensuing battle reveals Dalian’s treachery when he drains his people’s power for himself, killing them in the process. When Dalian’s people learn that he has been draining the river’s power, which is their life source, for personal gain, they turn on him. Dalian takes his own life to destroy the river once and for all, also destroying the gateway back to Tianxia and trapping everyone in the Netherworld.

Together, Liyen and Zhangwei stabilize the river with their combined magic, and Aunt Shou summons the Eternal Boatman, who provides the only remaining way out of the Wuxin realm. The boatman requires that they surrender all their memories to return home. The Wuxin collectively agree to give up a fraction of their memories to pay for their crossing. After returning home, Zhangwei proposes marriage to Liyen, and Tianxia is released from its service to the immortals.