Left 4 dead "The clones"

Hello. I love left 4 dead. You may love it too. This story changed my prospective on the game. I still play it frequently, but.. Have a listen. I was playing with my friends on a summer Tuesday morning. It was fun, as I loved expert. We went the first round, and I had to explain to my friend that on expert... you can not be reckless. He understood and we played a lot better. Second round comes and all was well. This time I did a lot better too. I knew how to fight tanks better. I did a lot more damage, and I healed my teammates. I didn't even lose any health! Then... the third round came. It was all fine.. until have way though a message came in chat by an unknown name. The name was just.. "___". I was freaked out when I saw a orange survivor. "___". I opened up the door. To my surprise it was another Louis. This keeps happening until my team is full of other survivors called "____". We were doing pretty bad. I shoot the gas tank.. exploded. Re spawned they were all still here? I was getting scared. I am a paranoid person.. but this was much more. We tried again, this time much more orange survivor's wanting to be free'd. We free'd them and they were all the same.. but they didn't seem like bot's. They talked in chat.. could bot's do that? They all spoke another language in chat. I couldn't understand. Half way through my friend gets pissed and starts killing them. As soon as my friend shoots one, he was instantly killed. I was freaked out and wanted to hurry up and beat the level. I pull the crane and we all run into the room. We kill of the zombies and all was well. They were all bundled in a room. I check the next room... tank! I say it in chat and tank a screenshot. Now.. the zoey "___" was doing death screams. She kept doing death screams and death screams. I was walking down the stair case killing zombies, then everyone death screamed. It was loud. During the sewers there was a witch. I knew this was it because there was no other way.. and about 50 survivors. All of a sudden "Witch death scream" The witch was gone? No body or anything. I climbed on the ladder.. all of a sudden fire everywhere. My friend hadn't said anything.. Then.. The fire was killing everyone! I wasn't gonna die. I took pills and ran to the safehouse. I was done? Everyone else was dead. I survived? No more rounds with these.. things? Then they all said "ipsum dolor sit non sciatur". Round over.. no music.. nothing.. just black. As soon as the next round started they were all gone? I searched everywhere.. but came to nothing. I was done. I couldn't play this. I was scared. So I quit. I couldn't deal with this. My friend asked me "What happened" I responded with the only thing that came to mind "The.. clones"