Bai Li Aria Song is an archeologist who heads into a desert expedition, often pausing to call her young daughter Bai Jia as the sand stretches behind her. In tandem, Jeong-in Bae Suzy works as a flight attendant and frequently checks in on her boyfriend Tae-joo Park Bo-gum, an astronaut, hoping to bridge the distance between their demanding lives. Both Bai Li’s family and Jeong-in are subscribers to Wonderland, an artificial intelligence system that lets people communicate with departed loved ones through simulated video calls. When the moment comes, Jeong-in brings the real Tae-joo home after he awakens from his coma, a turning point that blurs the line between memory and reality.
Hae-ri Jung Yu-mi, a Wonderland manager, spends her days fielding video calls from her own parents, who tease her about a relationship with her junior, Hyun-soo Choi Woo-sik. Alongside Hyun-soo, she handles difficult cases: a grandmother whose dead grandson in the Wonderland system is exploiting her, and Yong-sik, a dying man whom Hyun-soo suspects might be his biological father. The cases illuminate how the service can blur boundaries between family, loss, and manipulation, inviting scrutiny from every side.
Bai Li’s mother, Hwa-ran, grows tired of the service and considers ending Wonderland altogether, even as she contemplates telling her granddaughter that Li has passed away. Meanwhile, Jeong-in becomes uneasy with the changes she sees in Tae-joo since his waking, and she starts leaning more on the Wonderland version of him for comfort. Tae-joo’s behavior grows increasingly erratic, and at one point he is suspected of starting a fire in their apartment building, deepening Jeong-in’s misgivings. A wary Tae-joo even visits Jeong-in at her gate and learns of her Wonderland subscription, bidding her a painful goodbye as the moment of truth nears.
At the airport, Hwa-ran loses track of Jia, prompting a deactivation of the Wonderland service while search efforts unfold. Inside the program, Bai Li tries to leave and help locate her daughter, but she’s blocked by a series of obstacles in the simulated world. Undeterred, she drives through a brutal sandstorm, pushing toward the central operating system and causing glitches in other simulacra—even as Hae-ri and Hyun-soo race to halt the disruption. Their efforts culminate when Sung-joon arrives and grants Bai Li access to the central server, a move that reframes who can intervene in this digital afterlife.
With Bai Li moving onto the airport network, Hae-ri, who has already endured the loss of her own parents, empowers the plan by rallying Wonderland subscribers to help locate Bai Jia. Tae-joo answers the call, racing to rescue Jia, and the moment comes when the child accepts the harsh truth of her mother’s death. Jeong-in finally opens up about why she subscribed to Wonderland, a revelation that drives a difficult but honest reconciliation with Tae-joo. She then deactivates her Wonderland subscription, choosing a new, grounded path with him.
In the epilogue, Hyun-soo introduces his mother to the Wonderland version of Yong-sik, a moment that underscores how the line between life and simulation continues to blur for those left behind. This ending underscores the series’ core questions about memory, connection, and the cost of longing—and how a society built to bridge absence can someday reflect the deepest needs of those who remain.
