I expect the Marabar cave expedition is one of the most important developments in A Passage to India, which makes it very interesting to me that the entire scene seems concerned not with presence, but with absence. Adela feels somewhat empty at the beginning of the journey, the sunrise is devoid of wonder. When Mrs. Moore enters the caves, she feels everything reduced to nothing more than the sound “boum,” leaving her feeling lifeless and questioning religion. Adela realizes that she does not love Ronny; the middle ground between respect and basic attraction is missing. Various characters become absent throughout the expedition; first Fielding and Godbole miss the train, then Mrs. Moore decides to stay behind, Adela and Aziz leave everyone but a single guide, Aziz leaves for a bit, Adela goes missing, the guide runs off, and even when Adela is discovered she is absent from the rest of the group.  

The setting too plays a part, the caves that have no real special features, that lack carvings or paintings or really anything special beyond their existence. The basic idea of the caves themselves, their inherent absence. Even what truly happened to Adela in the cave is missing. The entire section is full of nothing, full of holes, full of absence.