The Cat Who Walks Through Walls by Robert A. Heinlein 388 pages published 1985.
I have always found Heinlein's books to be entertaining as well as thought provoking. Even in re-reading his stories I find the characters and circumstances interesting because it makes me rethink human behavior, society, politics, and religion. I don't always agree with his ideas, but they do make me think.
In this book, Dr. Richard Ames, an ex-military man and sometimes writer, is living in a privately owned space station. Not just a small habitat, but the home of thousands.
All is going well until a stranger sits down across from Ames at a nightclub table, and delivers a cryptic message “We need you to kill Tolliver by noon Sunday or we'll all be dead!”
This starts a seven day rescue mission that includes a marriage, a kitten that won't stay put, travel to four planets, a similar number of dimensions, time travel, and an invitation to hunt dinosaurs.
Another fast paced novel by the best selling dean of science fiction.