There’s a big jump from the submarine potboiler of 21st Century Sub to this book roughly ten years later. Herbert is firmly entrenched in hard SF, with a generation ship full of hibernating clones setting off from Earth to populate a planet of Tau Ceti. But the plot isn’t the most significant thing that’s been refined in the intervening decade. Bear in mind that Herbert had published Dune by now, with its inner monologs and shifting points of view and altered states of consciousness. Herbert must have had a lot of notes left over from psychology papers that didn’t make it into Dune, since he dumps it all into this book instead.
After the masterpiece of plot, character, setting and mood that is Dune, this book comes across as a bit padded, or rushed, or both. The premise mentioned above is solid enough (he went on to co-author a few sequels years later set in the same universe which were relatively well regarded), but the book reads like a play, or an old “base-under-siege” Doctor Who episode, since everything happens within the confines of the spaceship. Not that much different from 21st Century Sub in that regard, he even has a woman on the crew this time, but while that first novel dealt with a series of mishaps and challenges that its crew had to solve one by one, here the heart of the conflict is laid out relatively quickly. Previous spaceships have tried to make the same trip and all ended up disappearing. The protagonists are awakened early from hibernation because the ship’s onboard computers and their backups all go offline, as though they had achieved some form of self-awareness and couldn’t handle either the challenge or the loneliness of such a protracted trip through space.
It’s left to these people, who mostly have goofy names like Timberlake and Flattery, to jury rig some sort of artificial intelligence that has enough of a level of consciousness that it can pilot the ship without suffering the same fate as the others. Seems like a tall order given they’re already on the ship, and several of them are privy to information the others don’t have regarding their real circumstances and purpose. They can communicate back to Earth on a limited basis also, but that doesn’t seem to be very useful either.
What follows is over a hundred pages of ruminating about what is consciousness, the different forms that consciousness might take if it were developed artificially, and just how “conscious” are we humans in the first place? Herbert seems to throw out a couple of red herrings only to debunk them immediately, as though he were parodying similar plot scenarios from the sf pulps and how they could be an easy out for the author (i.e. “we’re not really awake ourselves”, or “there aren’t really any other colonists in hibernation, it’s just us”). Without much of what I could make out as an explanation, the end result is they arrive at their destination, which wasn’t necessarily supposed to have existed, in record time (as though the ship had the ability to “fold space”, like in Dune?), and the last bit about what happens to the ship computer once the colonists have something to colonize is a nice twist that definitely leaves the door open for more stories, which he eventually did.
What you have in the end with this book is Herbert being a little more didactic, writing a book that’s full of ideas about a particular topic but not enough of everything else to make it into a satisfying story.