(This is the same plot to the movie, just with a twist <3)

The Thing was already in the base and it had already assimilated 3 of the crew members, Bennings, Norris and Palmer, however, the others knew they had been assimilated and were The Thing so, MacReady and Childs had tied the 3 up in order to get some sort of answer or explanation for the situation

The others stood around, eyeing the infected trio carefully, making sure they didn't do anything to drastic

Garry now was whispering to MacReady, letting him know that they wouldn't kill Bennings, Norris and Palmer just yet. The older man seemed almost curious about the 3 and wanted to see what they would if the team kept them alive