Charlie Gordon is a man with an IQ of 68 that works in a box factory. He has friends there that actually just mock him and bully him, but he is unaware.
Climax
Charlie gets operated on and his IQ starts to rapidly rise as he gains knowledge quickly and develops a photographic memory.
Falling
Charlie begins to improve his intellect by racing against Algernon the mouse and other tests like the rohr shock.
Resolution
Charlie realizes that his friends just mock and bully him because they think he is dumb. He feels abused and taken advantage of.
Charlie slowly begins to fall in love with Ms. Kinnean, his teacher previously. Charlie begins to realize he is smarter than the people teaching him, and comes to the conclusion through his own research he will begin to regress back to his previous state.
Algernon dies as Charlie begins to regress. It is implied that Charlie dies as well, as every animal that underwent the operation also died. Tells people to put flowers on Algernon's grave.