This discussion may contain spoilers!
Post your theories about Carver here. Who is he? How is he connected to the group? How did he massacre the group at the Riverbank?
Here's my theory:
Carver was with the group before, as Carlos says in the preview. Apparently he's quite good with guns and weaponry, taking down all the people at the river bank, most of them being head shots. Considering the guy at the door in the Ep2 preview is Carver, I think he was in the military and/or was a hunter because of the camo jacket and gun
Pete also seems like a hunter because of the whole buck rifle story. He is also handy with guns and crossbows. Pete also says that the situation at the riverbank was FUBAR (which means Fucked Up Beyond All Recognition) Fubar is an old military acronym, was Pete in the military with Carver? Maybe. Also, Carver could also be around Nick's age and went hunting with him and Pete regularly, explaining his rifle skills. Either way, Carver is connected to the group, I think directly to Pete/Nick. We all know one thing though... He's a major threat.