Like others have been saying I'm worried that Yuri is going to get in Reiji's way. It'll allow Mao to escape and find Nagi to drag this story out. I have a weird feeling that Yuri will tell Mao where Nagi is too.
If Yuri backstabs Reiji like that, then she signed her death sentence on an even more gruesome way. But at least, that would trigger Reiji's desire to gtfo town, even if it's to rescue Nagi so they can die... however it won't happen like that, the story can't be dragged anymore. Ryou is rushing this manga and packing many events in just one chapter it's not farfetched to say the great climax will happen in chapters 178 and 179, with the following 3 chapters being the conclusion.
Abyss gonna be on another break the next week, maybe the penultimate or antepenultimate one, and the flags for the inevitable climax announcement (last 5 chapters) were already raised. If chapter 178 or 179 gets the opening color page (with the
these are the last 5 chapters text, 4 if it's on chapter 179), then the deal was sealed and we must be prepared for a tragic yet beautiful end.
What it may happen is that Yuri will indeed tell Mao where Nagi is with the intention of making both of them fuck off from The Town, Reiji will pick the intentions behind that and murder both of them or just Yuri if Mao gets his way.
If Mao drags Nagi outside of The Town, maybe a miracle will happen and Nagi would tell her uncle to go fuck himself and run back to The Town to wait for Reiji finding out she's waiting at the bridge.