Because TV characters never get to go on vacation without somebody dying. You never saw Murder She Wrote
They're somewhere on the Gulf Coast, just finished a case. Maybe it was a false alarm. But there's a hurricane hitting the Washington area, so they can't fly straight back. So Reyes books everyopne into a hotel, tells 'em they need to do a first draft on their reports, but other than that, have fun.
Pay no attention to the anvil on the ceiling.
You could probably come up with a better setup, but the idea is that you see the characters in a different state. And the ObAnomaly hits in a different way. Instead of reacting to a series of reports which set up a pattern, you're in the pattern. Can they spot it in time to save lives? Cue angsting.
Do the trap in another way: have the bad weather trap them in the hotel. There's all the cliches about slasher movies to play with. But these people won't make the usual stupid mistakes.
And if there's something happening that might be a Gamma, and they're trapped with it, who isn't going to wonder about Chaz and Hafidha?
Doesn't have to be the whole gang in the trap: the bad weather could be seriously messing with phones and the internet.
I don't think you could get away with the Ten Little Indians
trick. Then again, maybe the Gamma thinks he can.
Mix and add anvils to taste.