Charlie got invited to go to a party with his "friends". They made him drink and he got a little embarased.
Sorry Charlie, but we're going to have to let you go.
After the party Charlie gets deserted by his friends and his new found intelligence lets him realize they aren't his real friends.
Charlie rejoices after finally beating Algernon
P.P.S Please if you get a chanse put some flowrs on Algernons grave in the bak yard...
Charlie gets fired at work because his co workers signed a petition to get him terminated. They think that he has been acting strangely due to the operation, and that he changed from the old person he used to be.
Algernon is dying, and Charlie thinks the same will happen to him. He studies and researches everything he can to see if it will happen to him as well; and if it does, how to fix it. He is also sleeping in the lab temporarily.
Eventually, Algernon dies and Charlie no longer possesses his newly found intelligence. He writes his last journal entries before it all slips away.