I'm a bit wary of buying Niven's books these days: he started well as a writer but has weakened over the years. However, there was a chance that collaboration might produce something worthwhile, and I think it has.
The strange thing is that, although Lerner presumably did at least half of the work on this book (maybe more), it's virtually indistinguishable from pure Niven. Either they're naturally similar writers, or Lerner blends in very well.
The story is a prequel to Niven's award-winning Ringworld (1970), and it takes place in the 27th century, 200 years earlier than the events of Ringworld. It's mostly about relations between humanity and the alien race nicknamed the Puppeteers.
Hundreds of years earlier, the Puppeteers secretly hijacked a human colony starship with thousands of human embryos on board, and brought up their human captives as a servant race (known as Colonists) knowing nothing of Earth or human history.
Now this is starting to cause problems. Some of the Colonists are beginning to doubt the benevolence of the Puppeteers and are trying to find out about their own history. Meanwhile, the humans of Earth long ago wrote off the lost colony ship as an accident, but are trying to locate the Puppeteers' home world for other reasons.
The Puppeteers are very powerful, being numerically and technologically superior to humanity; but they are highly risk-averse herbivores and these developments strike them as potentially dangerous. Nor are they united: there are rival political factions trying to gain advantage from the situation.
At least at first reading, the story is gripping and highly readable, though it ends without a bang, as though the authors plan to carry on with it in a subsequent volume.
As usual with Niven, there are plenty of interesting ideas and situations, but the human characterization is weak. He has occasionally created distinctive human characters in the past, but the humans here are almost interchangeable. Fortunately the Puppeteers are more interesting; and there is another alien race that plays a small part in the story.
I wouldn't say this is a great book, but it's a satisfactory book that Niven fans should have no difficulty in enjoying. I wonder whether the gap between this one and Ringworld will be plugged by just one further book, or more...
Written in December 2007