Good book. It's a tale about an actor who is hired to impersonate a politician who has been kidnapped. His kidnapping threatens the relationship between Earth and Mars because the Martians have an intensely ritualistic culture that makes it impossible to just not show up for an impending important ceremony, and this politician is expected to participate in this ceremony.
I had a hard time getting into this book. For the first half of the book, I thought it was quite dull and was disappointed. I just wasn't caring about the actor - actually, he was kind of annoying, and he wasn't supposed to be annoying. But then around the midpoint, I suddenly got really into the story and quite enjoyed the rest of it. The ending was predictable, but it was a good enough tale that I didn't mind.
Excellent Read, Heinlein again succeeds in making you feel like you're in the story, from the moment the main character is recruited, right up to the end of the book. Not his best known work, but definitely worth taking the time to read.