Ka Chung and Lam Co Ying got separated when they were kids and one day, they encounter each other again in an unexpected situation. Yeesa wakes up from a coma a year after her car accident only to find out that things have changed in the present time. She realizes that she may come from another space-time.

In this space-time, Ka Chung is an author who has no memory of Yeesa. However, he constantly has dreams of a girl and he decides to turn his dreams into a novel. He asks Yeesa to be the illustrator of the novel, to which she agrees, wanting to know more about the story. Meanwhile, in another space-time, Ka Chung receives help from Lam Co Ying to get the only photo he has of his mom back from the scammers.

Ka Chung remains skeptical of Co Ying despite her offer to help him get back the photo of him and his mom. When Co Ying tells him about her ability to time travel, he does not believe her and thinks she is just making a fool out of him. Meanwhile, in this space-time, Yeesa starts to think that the Yu Ka Chung from this space-time is somehow connected to the Yu Ka Chung that she knows.

After learning about Co Ying's ability to time travel, Ka Chung and Ba Sai Gwai gather a few other New Age experts to help analyze Co Ying's situation. Ka Chung thinks Co Ying's time-travel ability may be related to the full moon. Meanwhile, Yeesa, in another space-time, believes that Ka Chung is the key to her returning to her original space-time when everyone tells her otherwise.

After her grandfather's death, Co Ying tries to travel back in time to save him. However, all her efforts are futile when she learns that she cannot change the past. Meanwhile, in another space-time, Yeesa reminds the Sacred Geometry Association of their true purpose, and Ba Sai Gwai and the rest decide to find the Lam Co Ying in their space-time to help Yeesa.

After setting up the association, Co Ying tries to persuade Ka Chung and the others to provide "Regret Repair Service" to the people, only to be rejected by Ka Chung. Out of desperation, Co Ying convinces the owner of the photo printing studio to allow her to help him, but things take an unexpected turn when it lands her in a hot mess that she might not be able to get out of.

After Co Ying's disappearance, Ka Chung and the others try to search for her everywhere when they stumble upon a shocking discovery that leads them to Yuet. Co Ying, in another space-time, meets someone she least expects there, while Yeesa finds the time capsule that Co Ying and Ka Chung had buried when they were kids.

Yu Ka Chung travels back in time to save Co Ying, and they discover the condition that triggers one's ability to time travel and what it takes to change destiny. Knowing that Yuet is going to try to change the past, they have to find him before it is too late. In another space-time, Yu Ka Chung tells Yeesa about the dreams that he just had, and that is when Ba Sai Gwai and the others start to put together the connection between both space-time.

In this space-time, Ka Chung, the writer, has trouble writing his next chapter because he stops having dreams about Co Ying. Ba Sai Gwai and the others decide to step in and help Yeesa, unaware of her real plan. In another space-time, Yuet does something gruesome with an ulterior motive unbeknownst to Mr. Cau and anyone else in that space-time. Seeing Co Ying in that space-time with him, Yuet knows the clock is ticking.

In another space-time, Yeesa and Co Ying work together to stop Yuet from changing the past. Co Ying knows that she will soon lose her memories, and she intends to sacrifice herself to give Ka Chung a different future, one that she has seen through the Lucid Dream Machine. In this space-time, after spending years trying to return to the space-time that she came from, Yeesa finally realizes what truly matters to her.