When you imagine humanity’s first contact with an alien, what do you picture? For me, it’s the optimism of classic sci-fi: ethereal beings slowly stretching out long-fingered hands from a glowing ship, a sign of peace and acceptance. Seth Dickinson doesn’t share my vision. In Exordia, his energetic, suspenseful melange of alien invasion and military action, Earth sits squarely in the middle of an intergalactic power struggle. If the aliens don’t get us, our own nuclear fallout might.

Anna Sinjari, a Kurd living in New York City, sees an alien in Central Park, basking on a rock in broad daylight. And Ssrin—the alien—needs her help, having been shot by another faction of beings. For some reason, Anna feels drawn to Ssrin, which is something the alien calls surendure: two souls existing as one. Anna begins to think of Ssrin as a friend, but their new partnership is barely formed when disaster strikes. Will Anna and Ssrin be able to fend off other alien agents and help save the world?

Exordia’s first act is its most successful. Anna and Ssrin’s initial interactions are personal, hilarious and thought-provoking. Once the broader storyline kicks in, however, it can be a struggle to keep up, so impenetrable are some of Dickinson’s ideas. If you are someone who loves a monumental level of specificity when it comes to military command structures or the complex metaphysical value systems of aliens, this is the book for you. Dickinson’s obsession with detail greatly enriches the atmosphere of Exordia, which rockets across many points of view and locations as various team members look for clues to unravel the mystery. But at times, the numerous technical terms and jargon practically wash over the reader.

However, Dickinson has crafted a number of very human stories in a book ostensibly about aliens. Trauma, morality in the face of disaster, forgiveness, guilt, lost love and the bond between parents and children all find their way to the page. Yes, these people are witnessing and trying to survive the craziest moment in the history of Earth, but their connections to one another ring true.

While some may wish it spent as much time with its characters as it does exploring its many fascinating ideas, Exordia is undoubtedly impressive. But there’s no question that it will be many sci-fi fans’ favorite book of the year, especially those willing to surrender to it, and be consumed.

Like Thunder, Nnedi Okorafor’s sequel to Shadow Speaker, returns to chaotic, post-apocalyptic West Africa and reunites readers with Dikéogu Obidimkpa, a mage currently leading a squad of special forces to liberate a camp of enslaved children producing chocolate.

To be more precise, it starts with Dikéogu introducing himself and the format of the book: transcriptions of voice recordings he made on a device called an e-legba. They vary in tone and precision, depending on Dikéogu’s state of mind when recording. It is a fascinating take on an epistolary novel, told by an often-unreliable narrator who frequently assumes that the reader knows more about past events than they actually do. He does explain where people like himself—called Changed Ones for their inhuman abilities, such as summoning thunderstorms, controlling the wind or reading people’s minds—come from and the prejudice they face. But the opening chapters focus on setting the tone for the rest of the story rather than exposition, trusting the reader to figure things out as they go.

A tale of mad mages and jealous lovers, of tyrants and demagogues, and of a catastrophe deferred, Like Thunder revolves around three people: Dikéogu, his old friend Ejii (protagonist of Shadow Speaker) and another Changed One named Arif. They are among the strongest Changed Ones, and reunite just as the peace treaty between Earth and its sister planet, Ginen—the peace treaty that saved both planets from destruction—is disintegrating. Dikéogu, Ejii and Arij are seeking a haven for Changed Ones, where they will be safe from the demonization of conservative internet pundits like Dikéogu’s own parents. And they are also caught up in a love triangle that may be crucial to saving the world.

Okorafor is an undeniable master of her craft, having won the Hugo and Nebula Best Novella awards for Binti and the World Fantasy Award for Best Novel with Who Fears Death, and Like Thunder is a well-written adventure story with surprising depths. Instead of drawing on the typical dystopian tropes, Okorafor relies on her signature blend of Africanfuturism (speculative fiction specifically about and written by people from Africa, as opposed to Afrofuturism, which focuses on African Americans), utilizing her familiarity with cultures from the Western Sahel to the Gulf of Guinea, and spiritual movements from the African diaspora such as Santeria. These rich mythological and historical influences add complexity to Okorafor’s work, but the relatively straightforward story in Like Thunder makes them easier to parse without prior knowledge. For anybody wanting an approachable—if not exactly gentle—introduction to one of today’s most thought-provoking science fiction writers, or anybody who just wants a good story told well, Like Thunder will more than satisfy.

Warm, imaginative and often funny, Annalee Newitz’s The Terraformers thoughtfully examines the price and cost of corporate colonialism and humanity’s ever-present need to expand.

In the distant future, Destry, a ranger who works for the Environmental Rescue Team on planet Sask-E, discovers a hidden city. Destry and the rest of her team are tasked with ensuring ecological stability on Sask-E, which is owned by the terraforming corporation Verdance, before Verdance sells plots of the planet’s land to the highest bidders. The ERT thought they were the only inhabitants of Sask-E. But the city Destry discovers is populated by an entire previous generation of terraformers, and she and the ERT consider whether to stand against Verdance and their murky motives. Centuries later, while a planetwide conspiracy threatens everything the ERT has done to turn Sask-E into a hospitable planet, the fallout from Destry’s conflict with Verdance resurfaces.

The Terraformers is an expansive, entertaining book, full of comprehensive world building and exacting detail. Every living thing in the terraformed areas of Sask-E provides data that flows back to the ERT: Messages can be sent through blades of grass or through water. Robotic drones converse with people, and genetically enhanced animals can communicate via text message. Newitz giddily explores the convergence of digital and ecological systems, and their enthusiasm is infectious. The Terraformers is full of parallels to contemporary issues (corporate greed versus environmental sustainability, the intersection of machines and humans), and while Newitz intensely examines these topics, the reader will never feel lectured, bored or disconnected from the characters.

But once The Terraformers concludes, the questions it poses remain. In our race to remake the universe for ourselves, what kinds of stewards will we be?

Ann Leckie’s Imperial Radch series is suffused with the kind of philosophical explorations typical of high-concept speculative fiction, including the nature of conflict, the desire for community and what it means to be human. But these books have also posed another question, one left tantalizingly unanswered: What are the Presger? The terrifying, technologically advanced but rarely seen aliens hover on the edges of the series, their former habit of ripping into spaceships and people alike held at bay by a long-standing treaty with humanity.

In Translation State, Leckie’s latest standalone installment in the Radch universe, three characters approach the question of the Presger from different angles. Enae is a human diplomat tasked with finding out what happened to a missing Presger emissary. Reet is an engineer who discovers he may be the scion of the long-lost leaders of an oppressed people. And Qven is a juvenile Presger Translator, one of the strange creatures that the Presger bioengineered to communicate with species they consider to be Significant, or worthy of a diplomatic relationship. Looming over it all is the approaching renegotiation of the treaty that keeps humanity safe from the Presger.

In some ways, Translation State reads like a witty, action-packed retelling of “The Measure of a Man,” a classic “Star Trek: The Next Generation” episode that debates whether the android Data is legally a person or a machine. The question here is not whether the characters think of themselves as Significant, but whether the Presger will think they are. Although the explicit stakes are legal, the terms of the debate are closer to theology than anything else. The Presger are essentially gods, with their treaty of nonviolence toward Significant species a particularly abstruse gospel. It brings to mind the Tarthenal from Steven Erikson’s Malazan Book of the Fallen series, who prayed to gods only to ask them to stay far away. Every party must make decisions regarding the Significance of other species based on not only what serves their own interests but also what will prevent the Presger from tearing everything apart. 

Despite the existential nature of its conflict, Translation State still has an essential optimism. Every character’s motivations are understandable, even if they are not sympathetic, as each person is genuinely trying their best under challenging and potentially lethal circumstances.

Translation State also has an absolute whirlwind of a plot. An aristocratic family’s fortune vanishes at a funeral in the first chapter, and later, Qven vivisects and devours multitudes of their fellow juveniles in what is, apparently, a normal part of Presger Translator development. (This book is not for the squeamish.) As ever, under all the excitement and plot machinations, Leckie uses contact among different species and cultures to discuss complicated constructs such as gender. For example, Qven’s initial confusion over how gender works mirrors the Radchaai inability to distinguish between genders in Leckie’s original Radch trilogy. 

However, if you are the kind of reader who wants all their questions answered, beware: I still don’t really know what the Presger are.

The Holy Vaalbaran Empire has ruled the small moon of Koriko for nearly a generation, imposing its will over her people with an iron fist. Like the rest of Koriko’s inhabitants, scribe Enitan has adapted to imperial rule, becoming fluent in the empire’s holy language. When her former lover is assassinated and her sibling, Xiang, goes missing, Enitan travels into the heart of the empire to search for Xiang. Once there, she is caught between two enormous forces. On one side, the Ominirish Republic, the Vaalbaran Empire’s only rival, asks her to spy on the empire in exchange for help finding Xiang. And on the other, the newly crowned Imperator Menkhet, God of the Vaalbaran Empire, has asked for Enitan’s help in exchange for the freedom of Koriko. To save her sibling and liberate her people, Enitan must strike a delicate balance and play a game of intrigue far more challenging than she ever anticipated. 

The Splinter in the Sky is an engrossing novel that captures, in impressive prose, the deep discomfort of living under occupation. Kemi Ashing-Giwa’s present-tense writing pulls readers deep into Enitan’s rich inner life, behind the mask she is forced to wear in order to survive. To achieve her goals, Enitan must stay silent in the face of being told that she’s not like the “other savages” and smile as members of the imperial elite auction off her people’s priceless religious artifacts. The result is a firmly anti-colonialist novel that doesn’t balk at examining how even the best intentioned colonizer can cause real harm to real people. 

Ashing-Giwa’s world, where even the God-Emperor is subject to manipulation and betrayal, is filled with political intrigue. However, it’s also a world where hope still exists. Even in the darkest moments of her journey, Enitan is propelled forward by hope—hope that Xiang is still alive and hope that she may be able to fulfill her mission and free her people.