Annie Besant brings readers on a journey through the planes of existence, explaining the interplay of the physical reality we perceive and the spiritual planes beyond our perception.

By quoting ancient documents of Buddhism and Taoism, Besant describes the composition and processes of the mysterious worlds beyond what we see and hear in everyday life. The divine wisdom of Theosophy includes doctrines from multiple ancient religions, such as those of Egypt, India, Tibet and Eastern Asia. In the eyes of the theosophist, each of these contributes truths to the phenomena of the physical, astral and mental planes which are explored by Besant.

Philosophical concepts of the Self, the soul, the afterlife, and reincarnation receive attention in the later stages of this book, which also explains the links between the planes and concepts such as the Buddha realms and Nirvana. Besant keenly summarizes and describes the major facets of theosophy, whilst praising the movement's founder H. P. Blavatsky.

Throughout this text, Besant's gifts for explanation and descriptive writing demystify spiritual mysteries and ideas that would otherwise be hard to comprehend. For years a leading proponent of the theosophic movement, Annie Besant published several books and delivered lectures in the early 20th century.