One fact holds true across all stories that feature time travel as a narrative hook: time travelling defies logic. No amount of exposition can explain away the plot issues that are created the instant wormholes are introduced. Being able to leap into the future or the past makes no sense whatsoever, so authors might as well make it seem cool, right?

Not necessarily. A lot of cool things do happen in Earth & Sky, the first instalment in the new sci-fi trilogy by Toronto author Megan Crewe, but the actual time travelling that animates the story is a thoroughly unpleasant and decidedly uncool experience – at least for the characters. Every trip made by 17-year-old Skylar, the book’s protagonist, causes her to almost throw up. And the negative effects aren’t all physical: hopping around in time also makes Skylar more aware of humanity’s bottomless talent for cruelty and stupidity. Bill & Ted’s Excellent Adventure, this isn’t.

Earth & Sky is a satisfying and impressively unusual, if not entirely graceful mash-up of gee-whiz adventure story and bleak existential drama. One of the most remarkable features of this tale of interplanetary colonialism and teenage derring-do is how often even the most heroic deeds result in failure, frustration, and death. Near the end of the book, Skylar waxes philosophic about her newfound wisdom: “After everything I’ve seen in the last couple days, I can say pretty definitively that life is messy, and inexact, and unfair, full of so many variables I could never take half of them into account. It’s terrifying, but thinking otherwise is just deluding yourself.” She comes to this conclusion while being hunted by hostile aliens at the scene of a notorious 18th-century massacre of Native Americans, which gives a sense of how Crewe’s story operates.

For most of her life, Skylar was just an average-seeming girl living in the American Midwest. Then, she encounters Win, a slightly odd boy who, it turns out, is an intergalactic time-traveller from a desolate planet called Kemya. Many thousands of years ago, the Kemyate people decided Earth might be a good place to resettle, and so planted a few colonists on its surface – the first humans. Being a highly scientific species, the Kemyates see colonization as a grand experiment, one they control by trapping the planet in a giant time field and manipulating its history, rerunning certain scenarios and cancelling out others. Win is part of a group of idealistic rebels who want to blow up the time field and free Earth.

So all of a human history is a lie, part of a grand conspiracy enacted by outside forces controlling people for their own ends, and who are being challenged by a ragtag guerrilla group aiming to shut the whole thing down. It’s a scenario with more than a little of The Matrix in its DNA. Earth & Sky even has relentless, murderous agents called Enforcers who pursue the rebels across time.

What does all of this have to do with Skylar? Turns out she is sensitive to shifts in chronology, which trigger panic attacks. Skylar’s sensitivity helps Win find pieces of the time-field-destroying weapon his leader has hidden across the globe and throughout history. Skylar isn’t quite “The One,” however – she struggles to get any proper respect from her travelling companion, who has been brought up to see Earthlings as lesser beings.

Win and Skylar – using a time machine that is part flying carpet, part invisibility cloak, part iPad – seek the missing pieces in the midst of violent historical battles and revolutions, which help hide their movements from the Enforcers. Crewe doesn’t use these scenes as an excuse to elucidate obscure moments in history; we are almost as lost as Skylar, never entirely sure why everyone is so intent on killing each other. The character connects the coldness of the Kemyates’ Earth experiments to the historical brutalities she witnesses: “It’s easy to see other people as hardly people at all when you’re watching them from a distance.”

Obviously, the fog of parable hangs heavily over Crewe’s narrative – there’s a lot here that relates directly to colonialism, cycles of violence, and even climate change. Some of these connections are subtle, others much less so: after a while, Skylar’s solemn monologues get a little tiresome. Earth & Sky is definitely for more melancholy readers who won’t mind that rebel victories come at a very large price. (It should be noted that the story features many acts of random violence, including the execution of a child bystander by an Enforcer.)

Though its sequels may bring a lighter or more triumphant note to the series, Earth & Sky occasionally risks being overly bleak. It has all of the illogic and plot inconsistencies shared by other time-hopping stories, but few of the compensatory thrills. What saves the novel is its abundance of genuine narrative tension and dread, and its uncondescending way of showing that actions have very real consequences – ones that cannot simply be undone by a convenient plot hook.