The book is intended as a thought-provoking meditation on the idea of the future. It asks questions about different aspects of the relationship between past, present and future, claiming that the connections between them may not be as clear cut as expected. It also touches upon the concept of time, which seems to influence the relationships between these three ideas, but which also complicates their seeming dependency on one another. It is also very concerned with the topic that the present might not actually exist. The rest of the book follows from this one intriguing assertion.