I'm speechless too. The knowledge that 8 people were in the room and Terri only knew 1 of them is absolutely horrific.
It reminds me of Hitchcock's movie "The Rope" where two young men kill a friend just for the thrill of having power over life and death. The two then throw a party to celebrate their achievement with the coffin serving as banquet table. (The movie is worth seeing, by the way.)
Even more, when you consider that battered and bruised Terri was saying to her friends that she wanted a divorce from that one person.