Episode Summary
The episode jumps to the future, revealing Gu Yangshan's death and leaving Ding Yi with a memento. In the past, Ding Yi learns Xian Biyun sacrificed herself. Gu and Ding Yi share a final goodbye at the airport as Gu is forced to flee to Taiwan. On the plane, Cao Yuanzhong reveals he has the codebook and knows Gu's secret. The codebook gets back to the mainland, saving Shanghai, but the victory sends a grieving Ding Yi into a dreamlike state where he reunites with his lost loved ones. Gu lives out his days as a spy in Taiwan, never to return.
Spoiler Alert
A Glimpse of the End
The episode kicks off with a time jump. A big one. We're years in the future, during China's "Reform and Opening-Up" era. We see Ding Yi. He's old now, and he looks completely defeated. Police officers approach him with news. Gu Yangshan has died in Taiwan. Before he passed, he made sure one thing got back to Ding Yi. It's the pair of glasses that once belonged to Joseph Needham.
This sends Ding Yi spiraling back into his memories. He's right back in the moment Xian Biyun died. You can tell he never, ever got over it. He remembers a lie Gu Yangshan told him. Gu claimed he killed Biyun himself. He also used a fake codebook to frame Luo Han as the communist mole.
The Airport Goodbye
The Truth About Biyun's Sacrifice
Back in the main timeline, the chaos continues. Ding Yi is hiding in the shadows. He overhears something that changes everything. The bullet that killed Xian Biyun really did come from Gu Yangshan's gun. Ding Yi instantly puts it together. Biyun chose to die. She sacrificed herself to protect Ding Yi. She hoped Gu wouldn't betray her love for him.
Gu Yangshan is also falling apart. He can't stop thinking about all the comrades who died to protect him on his journey. The guilt is eating him alive. At the same time, Cao Yuanzhong and his men are in a panic. They start burning documents, getting ready to flee the mainland.
A Desperate Search
Gu learns the real codebook was stuffed into a box. He bolts to the airport, absolutely frantic. He has to find that codebook to save Shanghai. He starts tearing through luggage, but it's no use. He has no choice. He has to get on the plane headed for Taiwan.
Ding Yi shows up at the airport too, wearing a disguise. The two men have a final, quiet moment. Gu gives Ding Yi a ring to remember him by. Ding Yi gives him the glasses in return. They promise to see each other again on the day the new China is founded. You just know it's a promise they can't keep.
The Codebook and the Aftermath
The Long Con on the Plane
On the plane, Cao Yuanzhong does something interesting. He mysteriously hands his own bag over to Gu Yangshan. Gu opens it, confused. And there it is. The codebook. The thing he was just desperately searching for was with Cao the whole time.
Cao acts smug about it. He claims this book will put them in good standing with Chiang Kai-shek. But it's all an act. Cao knows Gu is working for the communists. He's just waiting for the right moment to expose him. Gu tries to play it cool. He explains he was under house arrest for years studying the "Joseph code." He says he deserves some credit for his hard work. Cao just gives him a little smile. It's a smile that says, "I know everything."
A City Saved, A Mind Lost
Gu thinks back to the good days. He remembers laughing with Ding Yi and Xian Biyun. After the plane lands, a driver cleverly gets the codebook from Gu. The book makes its way back to Ding Yi.
They successfully use it to crack the Nationalists' bombing plan. Shanghai is saved. The city avoids total destruction. People pour into the streets, cheering and celebrating.
But Ding Yi isn't celebrating. He's lost in a vision. He sees himself walking through Shanghai, happily holding Xian Biyun's hand. He sees his dead sister, Hong Yu, looking young and innocent. He starts chasing after her. He follows her right into the old theater.
Suddenly, all his dead friends are there. They're alive. They scold him for being late to the stage and push him forward. And then he sees her. Xian Biyun is on stage, looking exactly like she did the first time they met. She walks toward him and gently takes his hand. She puts the ring on his finger. He looks out at the audience. It's filled with all the people he's lost and missed for so long. He's so lost in this beautiful dream that he doesn't want to wake up.
As for Gu Yangshan, he arrives in Taiwan and continues his mission. He becomes a sleeper agent with the codename "Yan." He spends the rest of his life there. He never makes it back home.
