Passage to India is divided into three parts: Mosque, Cave, and Temple.
Each part corresponds to an emotional and plot emphasis. In the first part, readers are introduced to the range of Moslem and British characters that are the primary focus of the novel. The single most important character in the novel is the Moslem doctor, Dr. Aziz. He encounters an important British character, Mrs. Moore, at his mosque. When he discovers that Mrs. Moore has known enough to leave her shoes at the entrance to the mosque, he feels a friendship for her that persists throughout the novel. She is in India to try to see to the engagement of her son Ronny to a young woman named Miss Quested. Dr. Aziz is a widower with three children. The two British women desire to see a more authentic side of India than what is possible through British clubs and theatre performances. Dr. Aziz arranges an excursion for them to the Marabar caves.
Although Miss Quested had begun to think that she and Ronny were not suited to each other, after a peculiar car accident in which no one is injured but in which the cause of the accident remains unclear, Miss Quested decides that she and Ronny are right for each other, and they become engaged.
The trip to the caves and the consequences of it are the focus of Part II. Mrs. Moore hears a strange echo in one of the caves and decides that the echo points to a meaningless in the universe. This unpleasant experience makes her want to return to England. Miss Quested somehow imagines that Dr. Aziz assaults her in one of the caves. She leaves hurriedly with Miss Derek, a British woman who has come in another car, without explaining her departure to anyone. Dr. Aziz looks for her, only to discover that she has gone. When the remaining group returns to the city of Chandrapore, Dr. Aziz is arrested for assaulting Miss Quested. The British are outraged at the assault, which they think shows the nature of Indians and confirms in their own minds the necessity of their presence in India. The Indians are also outraged at what is an unjust accusation and a difficult charge to defend against. Community relations are severely strained during the trial. The Moslem friends of Dr. Aziz arrange to get him a talented anti-British Hindu lawyer from Calcutta. As the trial is proceeding, Miss Quested begins to have doubts about her testimony. She develops in her own mind the sound of the echo heard earlier by Mrs. Moore in the cave. She recognizes that Dr. Aziz did not follow her into the cave and assault her. When she says this, the British case against Dr. Aziz falls apart, and they must set him free. Also, during this section, the news arrives that Mrs. Moore has died enroute to England. She died after departure from Bombay; the telegram came from Aden, and she was buried at sea in the Red Sea.
In the remainder of the novel, entitled Temple, a Hindu festival is celebrated. The reader learns that Mr. Fielding is going to marry Stella Moore, Mrs. Moore’s daughter. For awhile, Dr. Aziz has labored under the mistaken assumption that Fielding, his one British friend, is going to marry Miss Quested. They remain friends at the end of the novel, but things cannot resume their former status between the Indian community in general and the British in general. Nor are things exactly on the same footing between Fielding and Dr. Aziz.