An ex-soldier who is shell-shocked and insane. Often considered Clarissa's doppelganger, Septimus was a successful, intelligent, literary young man before World War I.
He is described as the first person who isn’t scared to talk about the war, about the truth of everything, and how it was to be in one step from death. There he lost his best friend Evans, and after that, he realized that he can’t feel anything else, that he is dead inside. The author doesn’t show him as a hero; he wants us to see what a sufferer he is, he wants to make us feel sorry to him.
You know, his whole transformation during the story is completely enormous: do you remember what a cute boy he was reading Shakespeare and poetry? But being a soldier he had to change completely, and from the boy who was so good he turned into a man who feels nothing, the war completely broke him. Also, he will never come back to the life he had before. Moreover, he completely lost his true faith to the empire of England. He couldn’t understand why people have to die? Why can’t we live in a normal society with love and respect? Septimus went to the dark side of his soul.
He moves back to London with Reiza (his wife), he returns to his job, but he slowly slips into further depths of despair and horror. He hears voices, namely of Evans, and becomes extremely sensitive to colour and natural beauty. The doctors compound his problems by ignoring them, and they become the embodiment of evil and humanity, in his mind. When DrHolmes pushes into his home to see him, Septimus throws himself out the window to his death.
Septimus Warren Smith in the Essays