The thing about trailers for later episodes as a sneak peek or news of characters appearing in other media before a show they are currently in has finished airring, is that it takes away the stakes. It’s the prequel trap—when you already know a character survives to make it to the "sequel," every life-or-death scenario loses its punch. You’re just along for the ride because you know for a fact nobody important is dying.
The main character here is not going to die. But this show is more than John not dying. This show is a what happened to Hal Jordan? Does John Stewart get the Green Lantern ring? Who are the bad guys? Why is Guy Gardner (yeah, why....) and what is it about this town that it has a big mystery surrounding it, what is it hiding and if the Guardians are involved somehow, how are the Guardians involved? This show is questions after questions, a relentless engine of answering one question only to hand you two more.
The episode starts with a slow burn for the first ten minutes before kicking into overdrive and letting all hell break loose. As Laura Linney’s character states so accurately "I believe the appropriate word to describe today's events would be: shitstorm!"
Hal leaves John locked in the car while he goes hunting for the Manhunter. With the timer expired, the entire town goes on high alert. Precision orbital beams start vaporizing the town to protect the cover-up, leaving Hal and John on desperate but separate, high-stakes missions—forced to navigate the chaos while their trust in each other completely erodes.