I loved the ending as is...without the additional bonus episode because the rest of the drama was so well made. Someone had mentioned in a comment that The Double had a theme of poetic justice. I posted this in response because it did ring true for me. Near the bottom, highlighted in blue, I give my reason for why the ending as is, did not upset me and why it was a happy ending for me. I know others feel different and that is fine. I just wanted to share my perspective.
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For me, i see the poetic justice in the following:
Vice is punished:
- SYR is selfish and uses evil means to gain power and XFF's love (after betraying and trying to kill her), but ends up with neither power nor love from XFF.
- WN wanted power and SYR's love, so went to great lengths to kill XFF and her family, but ends up losing it all to XFF (SYR's love, XFF's family survives, WN's brother dies, loses fake pregnancy, kills herself).
- Prince Cheng is a disciple of XH's father, who he killed. XH's father used his sword to teach Prince Cheng martial arts skills, but Prince Cheng ends up dying at the hands of XH, using his father's sword.
Virtue is rewarded:
- XFF gave up herself to help SYR become an imperial scholar (sold her guzheng to support him financially, sold her mother's pendant to get medicine and aid for him when he was sick, didn't go to school because she married him instead, etc.) and he betrayed her and tried to kill her. XFF remained true to herself with XH and he accepted her as she was. When he faced SYR alone, she returned to him because she didn't want to abandon him. In the end, she found love and happiness because XH returns to her alive. He too does not want to leave her alone and abandoned so he fights to survive. She also got her father and brother back and also gained new friends that support her.
- XH's father was killed in a battle against the Dai army because he was betrayed by Prince Cheng and his cohorts. XH brings them all to justice. He battles against the Dai army for the country (selfless compared to SYR, WN, and Prince Cheng who are all selfish). The difference with his father is that his father wins the battle, but can't leave safely because Prince Cheng blocks his retreat. For XH, he is in a losing battle, but throughout the drama, he helps others (Emperor, Situ Jiu, XFF and her family) who made it clear throughout that they would never abandon him and would do what they can to help him. So, that's why it is a clear happy ending for me and why the battle scene does not upset me. Knowing the characters and how well their relationships and character are developed throughout, it's clear that XH wouldn't die, his friends wouldn't abandon him. It is also poetic justice.
- As a couple, XH fights to survive because he knows XFF is waiting for him and he wants to return to her. So he lives, he returns, and he and XFF, who both suffered at the hands of selfish people, both live, finding love and happiness.
The part that doesn't seem fair though, are the deaths of Tong'Er, Lu Ji, and Wen Ji. I don't understand why they would die, given the poetic justice theme. Unless it's to say that some of the innocent and virtuous can't be rewarded because they fall prey to the evil and maliciousness of others. ?♀️