In a nutshell, this is a time travel story. As with most Heinlein works, however, there are a number of serious twists to this classic sci-fi sub-genre. The first method of time travel is used by the protagonist, Dan, is cryogenics, but one of the major twists is that this is not how he travels through time the second time around. I won't reveal more for fear that you, dear reader, would be robbed the pleasure of the surprise. Dan is an engineer, a real innovator with an aptitude for solving practical problems that have market demand and better the lives of people. He makes some bad choices in the social sphere, however, and ends up in being screwed out of everything to his partners in his first major venture.
As with all Heinlein novels, the reader gets a good dose of common sense ethics, business practices, and social critique throughout the novel. Unlike some of his other, more provocative and controversial novels, his authorial instruction is fairly subtle, and delivered with a smooth narrative style by Lawlor. One of the most striking things about this book, however, is that as much as I liked and could relate to Dan, the most memorable character in the book was Dan's cat: Pete. Heinlein often has some wise, old man archetypal character in his novels through which he delivers his social and intellectual critiques. I would argue that in this novel that wise, old man is none other than Pete the cat. Read the book, or listen to the audiobook, and let me know what you think.