honestly i highlyy recommend u to read on your own (vol 3 ch 6) but basically:
- we hear more of mc's thoughts when he found the files. the contents were also written in detail
- chimera had violent reaction when he saw a certain file, mc asked whats wrong
- he's a fish chimera sort of so when on land he cant talk properly, mc told him to go back into his tank to speak clearly
- mc was gonna go inside tank with him and that's when chimera got shot
- mc had a bigger reaction to that because he was so close to learning important stuff + felt really bad for the poor chimera
i think that's all i can say because i swear the details that are left out reveals a lot of things that makes readers go "OH"

I love the manhwa adaptation and it’s why I read the novel in the first place but it skips so much and you really don’t get to see much of Kang or Kim Muhyeok’s thought processes. There’s a lot more depth to the emotional conflicts in the novel that the manhwa just straight up doesn’t include. I totally recommend yall go read it (๑•ㅂ•)و✧