This is the fourth, and (currently) final book in the series.
There was a delay of a few years before this was released, and the tone, length and feel of the story is quite different. This is not a bad thing.
It feels like he could have written any one of a hundred stories about the Bobiverse at this point, and focusing on this particular story is a very deliberate decision, and a nice way to end the series by tying up a loose end from earlier in the series - what happened to Bender?
He was one of the earliest generation Bobs and went missing a couple of books ago, never to be heard of again.
Bob-1 goes and searches for him, his time with the Deltans having come to a bittersweet ending.
What he finds is quite incredible, and it takes the entire volume and every resource, technical and otherwise that Bob has, to uncover this new mystery. It's not a Dyson Sphere this time, but a Totopolis!
A new species of intelligent life is discovered, but it's very difficult at first to figure out how advanced they are, given their star circling abode. And it's not clear if there isn't a third party responsible for putting them there.
It's a clever way to wrap up, the story and event are only possible because of the advances Bob has made thus far.
Whilst all this is happening, there's rebellion afoot. Bob's have replicated so far that they are drifting in personality, and this isn't always a good thing.
Some very interesting questions are asked about replication, some kind of quantum entanglement means that no two Bobs can be identical, and the ramifications of this are quite profound.
I honestly don't know if I want another book, this one does a good job of concluding the story, but one of the great things about infinite replication in a big old universe is that there's so much to write about.
I predict a fifth book, pickling things up a few centuries later, or a quest to find an alternative Earth in the infinite cosmos. I know I'll read it.