Last year I reviewed Impulse, the third book in the Jumper series by Steven Gould. I’ve just finished Exo, the fourth. Yes, I’m still a way behind in my reading.

As in Impulse, Exo follows the activities of the Rice family: parents Davy and Millie, written in third person, and their 17-year-old daughter Cent, in first person. All three have the ability to jump – teleport – from place to place, subject to some plot-enabling constraints. In my review of Impulse I suggested Gould seemed to be moving pieces around in preparation for something bigger, and Exo is definitely that. I wasn’t expecting quite how big.

Impulse was Buffyesque: teenage girl with powers has to deal with school, boys, villains, etc. Exo has more ambition. The scope is not local, but global. Exo is about a young woman taking control: knowing (mostly) what she wants, and setting out to get it. Emerging from the shadow of her parents, from the shadow of their necessarily secret lives – they have enemies, trailing them through the books, who’d rather see them dead than jumping.

What does Cent want? Consider this: she can jump to places she can see or has visited. She can also jump “in place” adding velocity. So she can jump up, and keep going, adding bursts of speed to counter gravity, and then she can jump instantly back to where she started – and then instantly back to where she ended up. With the necessary equipment, how far up could she go? And what could she do when she got there?

And of course: what happens when, inevitably, she’s tracked?

Cent is a convincing protagonist, albeit implausibly bright. She still has to endure late-stage teenagerism with its embarrassing parents and boy-related awkwardness, even as she steps and/or jumps towards adulthood and the accompanying Stuff. I’m pleased she’s not the only focus: the many chapters following Millie and Davy broaden and support the story, linking it to the previous books and showing more of that Stuff. For example, Millie’s mother is very ill in hospital – and they suspect their enemies know, which brings obvious and non-obvious complications.

Gould doesn’t skimp on the technicals. Exo is a little heftier than its predecessors, and much of that seems down to the fine detail, the research brain-dumps he scatters throughout the story. Perhaps these are intended to appeal more to the teenage boy audience, to balance the female protagonist viewpoint. I know my proto-nerd self would’ve lapped up every nut and volt. It doesn’t feel like padding, slowing the story down. Instead it grounds the story in the real world: despite all the jumping you still need X and Y, and you still can’t do without Z.

What’s missing, curiously, is any great sense of threat beyond the dangers Cent experiences as a natural result of her ambition. The Rice family’s enemies are always in their thoughts, and Davy especially is constantly on his guard fretting about attack vectors, and that’s mostly as far as it goes. Not entirely. Perhaps that’s a more realistic approach than an attack-of-the-chapter style, which would only submerge the main plot in treacle. The reader wants to know what Cent does next, and that’s enough to keep the pages turning.

Exo marks a change in the Jumper series. The previous books were about dealing, struggling, adjusting, fighting. Exo is about owning and achieving. It’s positive, it’s progressive, and you’ll wish it were true. On the flip side, I’m not sure where the series goes after this. At least if it ends here, Exo is a fine conclusion.