DOOM is the 36th chapter Ajin: Demi-Human, created by Gamon Sakurai.
The chapter begins with a flashback to when Kei and Nakano were being driven to the forge security building. Kei warns Nakano to try not to be decapitated and explains to Nakano what happens to him if he got decapitated.
At the present time Kei drops back onto the floor and Sato comes around the corner and announces that he decided to show up. Kei asks Sato how he was able to do what he did and Sato answers that he isn't bothered that he died. Sato wonders to himself what Kei's plan was and tells Kei that he was still going to assassinate Kai Keiichi and Li Naomi. Sato openly challenges Kei to try to stop him right before. Due to a gas an explosions kills all three of them before anyone is able to do anything and Sato escapes to a different area.
Kei wakes up and quickly realises that the fan has been destroyed. Kei figured that since Sato didn't know Kei's plan that Sato simply decided to destroy everything there. Nakano questions what their next move should be.
After being revived, Sato kills a small group of police officers and takes their weapons and handheld radios.
Kei asks Hirasawa what you're supposed to do when you're completely outnumbered and Hirasawa responds that the best method is guerrilla warfare. Kei points out that they are in control of the security room and that they are able to track Sato's movements. Izumi spots Sato on the screen and Tosaki informs Kei that Sato is in the electrical area on the 10th floor. Kei immediately realises that Sato's intention wasn't to destroy Kei's plan but to destroy backup power generator so when he cuts the main power supply everything will shut down.
Sato's IBM secretly contacts his inside man and instructs him to feed them false information about his location. Sato gets ready inside a locker room and spots a scally cap and puts it on preparing for battle.