The final book in the series that starts with Worldwar: In the Balance.
Homeward Bound is the less than stunning conclusion to Harry Turtledove's series about an alien invasion of Earth. It's set in the near-future where America has maintained its independence (mostly) and sent a space ship to the alien invaders' home world.
This review will not contain major spoilers.
Homeward Bound is like the previous book in the series. Not a whole lot happens. It's a good conclusion to the story, it just doesn't cover a lot of ground. Since the human characters are traveling around the universe at high speeds, sometimes frozen in a space-traveling hibernation, a lot of the book is just about how weird it is to outlive everyone and see the effect of so many generations.
It definitely leaves room open for even more sequels, as the large questions characters wrestle with about the future of earth and the alien planets are left largely unanswered. As far as I know Turtledove is leaving his options open to write additional sequels!
It's getting a little old how Turtledove keeps recycling the same few characters. Sam Yeager, for example, was in every single book from when he was a young baseball player to when he's like 200 years old based on time spent frozen or going light speed. And even small characters are the ones that just happen to come up again and again when it would make more sense if importance were diversified a little.
All in all this is a fun book, and if you've made it this far into the series you'll probably enjoy it!