As we have mentioned repeatedly, the secret ending in Little Nightmares 2 leaves many questions unanswered. However, after gathering all the theories together, we have come to the only somewhat plausible conclusion and explanation. 

The World and Story of Little Nightmares 2

Other theories about Six's shadow and whether it is a sequel or a prequel can be read in this article. And now let's find out why Six betrayed Mono in the secret ending. 

Why did Six let go of Mono's hand?

So let's remember the moment when we rescued Six from the Hunter's clutches. The scene was as follows: a little girl sitting, scared, hiding. There was a small music box next to her (which is important). When Mono reaches her with good intentions, she runs away. The question is, why? Didn't she want to be free?

There is a city television tower depicted on the wall. It is quite likely that she had been in the city before and perhaps intentionally escaped from there. After that, true teamwork and struggle for survival begin. 

However, after entering a residential house following the hospital, the Thin Man appears before us. If you don't know, it has already been shown in the ending that the Thin Man is Mono himself, which is why everyone talks about a time loop in the game. So, what happens next?

Is the Thin Man Mono?

The Thin Man (aka Mono) takes Six away, and Mono begins his journey through the screens in search of his friend. Here's what happens next: Mono ends up in the city, and the Thin Man, whom our hero successfully destroys, appears before him. 

Then we find ourselves in a pink room with a long staircase, where we find Six in an enlarged and slightly deformed form. She is holding that same music box in her hands, and there is a childish atmosphere with pink lighting and a bunch of toys around her. 

And here comes a logical question: does she even want to leave from there? No. She behaves exactly as she did in the Hunter's cabin. It gives the impression that this pink room is her world of fantasies, and the music box is the delicate thread that keeps her between the real world and the world of dreams. 

And then Mono starts crushing her last hope, the music box. Why? Because Mono believes that she needs to be saved and that freedom is more valuable than anything. However, Six apparently does not think so. Judging by what we see, she always wanted to stay in her pink world, far away from the disgusting and zombified city.

Six just wanted peace

Then they both run out of the room together towards the exit. However, Mono doesn't make it, and Six lets go of him. It's a very sad and truly magnificent scene. But Mono survives, enters a room with eyes, and transforms into the Thin Man. 

And now we come to a logical conclusion: the Thin Man (Mono) has realized his mistake over the many years in the time loop and tried to correct it somehow - to save Six from himself. Now we see a closed loop where Mono, in the form of the Thin Man, tries to correct his past mistakes. 

We will have to wait for Little Nightmares 3 to find out if our speculations were indeed correct.