o the serial killer abducted that one cop who _ as you could see in the flashback - is a violent rapist. He repeatedly beat the crap out of the guy and raped him under the pretense of education (probably his brother or lover idk). So he is not a good person. The serial killer brought him in as a means to kill some time and also test the mcs dedication you could say, whereas the other dude who is held captive is more of a bargain, so that the uke is bound to stay and be obedient because otherwise he would kill the dude. now for the final panels: the guy who was beaten and raped by the cop who is now with the serial killer was actually the programmer and hacker we saw in previous chapters who worked together with the mc and they got the glasses with the camera which sends live footage to his computer apparently (since the last one he wore did not broadcast it live and the footage was destroyed when the mc and the killer were in the shower the mc and hacker must've worked out a different strategy to be sure that the footage is safe even if the glasses are destroyed) so the hacker is has the evidence now that the author is a killer or at least abductor and is now proceeding with the plan the two of them probably worked out together to blackmail him and ultimately gain control of the situation.
Wait what ;-; i don't understand (⊙…⊙ ) can someone pls explain