
Well let’s see huimin seo was trapped into this novel,he knows the future yada yada and since he acts way different from the original character hes diagnosed with split personality disorder, on the other hand we got iheon cha who also somewhat knows the future (but he doesn’t know anything about the novel) he went back in time and I believe he wants to make sure huimin doesn’t (re)gain memories of the original huimin(or the “other personality”),
anyway that’s what I picked up but if I’m way off well that’s unfortunate

Apparently, There're 3 timelines: The timeline where the og novel happened (1st timeline), the school life timeline(2nd timeline where everything is normal), the current timeline we see(the after 3rd timeline Iheon and Huimin).
Huimin thinks of first timeline as a novel despite he was the one experiencing it and created 2nd timeline out of trauma.
yall i really don't understand shi