A devastating car accident leaves Kai Xiang with no memory of who he or his wife Xiao Qi, is. In an effort to recover lost memories and rekindle their love, they decide to undertake the journey where they first fell in love; on the Trans-siberian railway. Together with Kai Xiang’s best friend, Kenneth, the trio travels from Beijing to Moscow, each in search of answers to their own questions. However, retracing their steps and visiting old...

Their journey takes them to Ulaanbaatar, Mongolia where Xiao Qi and Kai Xiang met for the first time five years ago. Still reeling from his break up with Kloudiia, Xiao Qi promises to help him win her back and thus began their adventure. Following the clues of Kai Xiang’s memory, they arrive at a vast abandoned field. On the way out of there, memories of Kloudiia start to creep into Kai Xiang’s mind. The confusion overwhelms him causing him to...

All hope seemed lost in the blistering cold but thankfully, a kind shepherd found them and provided shelter, warm Mare’s milk and Mongolian hospitality. Kai Xiang finds a moment alone with Kenneth and apologizes for putting them in danger, where he unknowingly learns of Kenneth’s feelings toward Xiao Qi. At dusk, Xiao Qi finds a teary-eyed Kai Xiang next to her; she’s taken aback and touched. Are her efforts finally being acknowledged?

Xiao Qi searches for answers at the bottom of a bottle and finds herself in the arms of Kenneth. He remembers the day Kai Xiang left her at the altar. Ever since then, Kenneth has stayed by her side faithfully, all while struggling with feelings of unrequited love for his best friends fiancè. Upon reaching Baikal, the trio follows the clues to a café, where they find out from Kloudiia’s cousin, Jessica that Kloudiia has been missing for the...

Jessica further recounts what happened all those years ago and the trio is shocked to learn that Kai Xiang is actually a father. The revelation leads Xiao Qi to wonder if she’s delivering Kai Xiang back into Kloudiia’s arms. Under pressure and so much heartache, Xiao Qi decides to leave, leaving Kai Xiang and Kenneth to search frantically for her. Kenneth reveals to Kai Xiang his past with Xiao Qi, leaving Kai Xiang to feel immensely guilty...

The pair eventually finds Xiao Qi in Shaman Cape and Kai Xiang and Xiao Qi tearfully embrace. After going through so much, Kai Xiang opens up to Xiao Qi and the two share a moment. On arriving in Irkutsk, the trio checks into a hotel that Kai Xiang and Xiao Qi had visited five years ago. Kai Xiang starts to regain some of his memories with Xiao Qi and they head to a restaurant to celebrate, but Kenneth soon finds a peculiar photograph hanging...

The next morning, Xiao Qi takes Kai Xiang around Irkutsk in hopes of jogging his memory. They stop by the local market they explored five years ago in their search for Kloudiia. It was there and then that they had started to develop feelings for each other all those years ago. That night, Kenneth decides to pass Xiao Qi the photograph he found. Meanwhile, Kai Xiang is washing up in the bathroom when he starts to see horrifying visions of him...

Kai Xiang is horrified at what he saw. To comfort him, Xiao Qi shows him the photograph of Kloudiia and a small boy to prove that Kloudiia is not dead. The trio decides to return to the restaurant for answers and discovers that Kloudiia had indeed brought her son to the restaurant. Kai Xiang is left with more questions. Why was Kloudiia covered in blood? And where did the child go? Xiao Qi suggests that they head to Moscow to find answers....

Upon arriving in Moscow, the trio hit the ground running, asking locals about the name of the lullaby. At last, a busker triggers some of Kai Xiang’s memories. The lullaby was something Kloudiia sang to her son, An Ran. They turn to Kloudiia’s alma mater where they manage to get an address off an old friend. The landlord reveals that Kloudiia once tried to commit suicide here.

After finding Mei Ling, she reveals that she met Kloudiia in church. Kloudiia had turned to the church to help cope with her grief of losing An Ran and the reason for Kloudiia’s suicide attempt triggered Kai Xiang’s memories to flood back in. While Kai Xiang was preparing for his wedding, An Ran had a terrible accident that left him fighting for his life. At a loss of what to do, Kloudiia begged Kai Xiang to return to Moscow to see his son...

Kai Xiang finally remembers all the painful memories. After An Ran passed on, Kloudiia found it hard to move on and attempted unsuccessfully to take her own life. After she was recuperated, she left Kai Xiang without saying goodbye. Mei Ling told Kai Xiang that An Ran’s death anniversary was coming up. Kai Xiang visits An Ran’s grave and discovers a family portrait his son drew. 凯翔终于记起了那段痛苦的时光。当时，他逃离婚礼，十万火急地赶到医院探望病危的儿子。那也是他和Kloudiia陪着安然，度过他短暂人...

On An Ran’s death anniversary, Kai Xiang meets up with Kloudiia. The two catch up while acknowledging the distance that now separated them as strangers. Kloudiia summons all her courage and tells Kai Xiang the true reason why she left without a farewell. The two embrace as they finally let go of all the pain and trauma. Kenneth can no longer keep up the facade, and confesses his feelings to Xiao Qi, who remains undecided between the two.

A devastating car accident leaves Kai Xiang with no memory of who he or his wife Xiao Qi, is. In an effort to recover lost memories and rekindle their love, they decide to undertake the journey where they first fell in love; on the Trans-siberian railway. Together with Kai Xiang’s best friend, Kenneth, the trio travels from Beijing to Moscow, each in search of answers to their own questions. However, retracing their steps and visiting old...