In The Last Colony we return to the universe inhabited by John Perry and Jane Sagan, our heros from Old Man's War and The Ghost Brigades. They are happily married, retired from military duty, and living the comfortable life of civil servants while raising their teenage daughter. Of course, this can't last.
Like the previous books in this trilogy, the plot moves along swiftly. Scalzi gets more action into a 300 page novel than many of his contemporaries can get into 600 pages. The thing I really like about Scalzi is that even though his characters inhabit a future world with technology we can barely imagine, they (the humans anyway) are still just people who act more or less like you or I would in the same situation. Bacon even makes an appearance in the book, although I have no idea if that was inspired by the infamous Bacon Cat incident.
Compared to the two earlier chapters of the trilogy, this book has less shoot 'em up military action. The action here is really more political intrigue as Perry unravels the conspiracy that he has gotten his family mixed up in. So it's a little different than it's predecessors, but you'll still have problems putting it down once you start reading.