Before the book was published, the author wrote a very popular article in the NYT...you can look it up.
I read the book and it's amazing. It's about the author's process of dealing with her husband's MLC, which ends with them reconciling. But I don't recommend reading it as a guide to recovering a marriage when a person is in MLC. Her intention in the book is to write about how she dealt with a life crisis by working on herself, letting go, choosing to not put her life on hold, but also standing for her marriage (in a time-limited way BTW!). It's an inspiring read.