The book is the only novel written by Sylvia Plath. The plot is the story of a mental breakdown, has autobiographical elements and is often considered to be parallel with the authors own fight with mental illness. The general mood of the novel is depressive and gloomy. The two elements of the illustration are the jar and the human heart. The jar is self-explanatory while the heart enclosed within symbolizes the author’s suicide which she committed shortly after the noel was first published.

„A bad dream. To the person in the bell jar, blank and stopped as a dead baby, the world itself is the dead dream. I remembered everything. I remembered the cadavers and Doreen and the story of the fig-tree and Marco’s diamond and the sailor on the Common and Doctor Gordon’s wall-eyed nurse and the broken thermometers and the negro with his two kinds of beans and the twenty pounds I gained on insulin and the rock that bulged between sky and sea like a grey skull. Maybe forgetfulness, like a kind snow, should numb and cover them. But they were part of me. They were my landscape” 

The color theme reflects the dark and gloomy mood of the novel. The sea resonates with the hopeless depth of depression and the endless fiht with one’s own mind and the demons within.

„There is something demoralizing about watching two people get more and more crazy about each other, especially when you are the only extra person in the room. It’s like watching Paris from an express caboose heading in the opposite direction–every second the city gets smaller and smaller, only you feel it’s really you getting smaller and smaller and lonelier and lonelier, rushing away from all those lights and excitement at about a million miles an hour.”