Swarm by Scott Westerfeld, Margo Lanagan, and Deborah Biancotti was published in 2016 and is the second installment in the Zeroes trilogy. This YA science fiction series follows a group of teenagers with unusual superpowers that are as much burdens as they are gifts. In Swarm, the stakes escalate after the events of the first book, as the Zeroes face new threats not only from society and law enforcement but also from others like them—equally gifted and potentially more dangerous. Set in a gritty, alternate California city, Swarm explores what happens when a new breed of powered individuals begin to emerge, throwing the fragile equilibrium of the Zeroes’ world into chaos.

Plot Summary

The last Saturday before Christmas pulsed with energy on Ivy Street. The clubs hummed with anticipation, the streets teemed with people hungry for distraction, and Ethan Cooper – better known among his crew as Scam – let his second voice charm and manipulate the crowd with honeyed lies and perfectly timed truths. That voice, a mysterious entity separate from Ethan himself, knew exactly what to say to get what Ethan wanted. Tonight, what he wanted was a packed dance floor at the Petri Dish, the Zeroes’ underground sanctuary. But more than that, Ethan wanted Kelsie’s heart. The girl who soothed his chaos, the Mob to his Scam.

Kelsie had found a strange kind of solace in the Dish. There, behind the DJ booth, she could feel the crowd through their joy, shape their emotions, and turn chaos into unity with the drop of a beat. It was more than a club – it was an experiment. Their leader Nate, known as Bellwether, ensured everything was in balance. Lights synced with emotion, the music calibrated to the curve of the night, the crowd engineered into euphoria. With the others – Chizara the Crash, who could destroy machines with a flick of thought, Thibault the Anonymous ghost among them, and Flicker, blind but all-seeing through the eyes of others – they had forged a fragile rhythm, a system of synergy and control.

But that balance fractured the moment Ethan crossed paths with Sonia Sonic. The girl with a phone full of conspiracies and a determination to expose them. She had seen the Zeroes before, caught Ethan’s voice on video, and now she stood on Ivy Street, snapping photos and asking questions. Despite every warning, Ethan let her in. He hoped that Kelsie’s presence and the energy of the crowd would cloud Sonia’s judgment. Instead, she became a witness to a night that would spiral into unrecognizable terror.

Inside the Dish, the air throbbed with heat and rhythm. Chizara controlled the lights like a conductor guiding a symphony. Kelsie’s music wrapped around the crowd like velvet. Flicker moved behind the bar, glancing through borrowed eyes. Thibault hovered at the edge, unseen, but vigilant. Even Sonia, skeptical and sharp, seemed to succumb to the seduction of the night. And then, in the shifting shadows, a couple emerged.

They moved together like magnets caught in a current. The boy – tall, half-shaved, radiating charisma – and the girl – delicate, intense, trailing her frilled skirt across the dance floor. When they locked eyes, a white-hot connection pulsed between them, slicing through the Dish like a blade of light. As they spun, their shared intensity grew until it eclipsed everyone else. Where Mob once unified the crowd, this pair shattered it. The energy that once flowed outward from Kelsie and the Zeroes was now sucked into the vortex between the strangers. The unity fractured. The rhythm dissolved. Recognition vanished.

First Ethan’s voice glitched, speaking nonsense and unraveling him from within. Then Crash stared blankly at her control board, wires and switches foreign to her fingertips. Mob’s records melted into gibberish, her turntables turning into gnashing mouths. Flicker forgot how to read Braille, forgot Thibault’s face, forgot his name. Across the Dish, memories frayed and identities dissolved. The crowd stumbled, their movements jagged and terrified, puppets cut loose from their strings.

Nate felt the shift the moment he stepped through the doors. Gone was the web of attention he so carefully cultivated. The crowd no longer bent toward him – they spun wildly, untethered, flailing in panic. And in the center of it all, the couple continued to dance. Their love, or whatever power surged between them, bent reality. Even Nate – the master manipulator – could not seize control. He reached the fuse box, and with the last fragments of clarity, he pulled the lever.

Darkness fell. Silence followed.

In the blackness, order returned. The voice stopped. The music ceased. The spell was broken, and the Zeroes emerged from the wreckage of their own sanctuary. Chizara climbed from the booth, Kelsie from behind the decks. Nate’s voice steadied the crowd. Together, they scanned the faces, searching for the ones who had done this.

The couple tried to leave under the guise of panic. The boy cradled the girl like she was wounded, but their composure gave them away. Chizara chased them through the crowd, calling out the truth. The girl smiled, blew a kiss, and Chizara staggered – the walls bent around her, the lights warped, the people twisted into alien forms. By the time she recovered, the couple had slipped into the night.

The damage was real. Lights smashed, people bleeding, the unity of the Zeroes cracked. But there was no time to mourn. Something new had entered their world – not just Zeroes, but others like them. Others whose power didn’t fit neatly into the experiment. Others who were chaos incarnate. The Petri Dish, once their safe space, had been violated. And the ones who did it were still out there.

They called themselves Swarm.

The group gathered again, shaken but alive. The crowd had scattered, and Sonia had more questions than ever. But this wasn’t the end. It was the start of a reckoning. The balance they had built was no longer enough. New Zeroes had arrived – dangerous, unpredictable, and powerful enough to bend the rules of their world. If the original six were to survive, they would have to evolve. Trust would be tested. Control would be challenged. And the city of Cambria would never be the same.

Main Characters

• Ethan “Scam” Cooper: Ethan possesses a “voice” that knows exactly what to say to manipulate others, though he often has no control over what it says. Scam struggles with the duality of himself and his voice, which speaks his hidden desires and fears. In Swarm, he’s haunted by past mistakes and desperately tries to win Kelsie’s heart, even as his voice endangers the group.

• Kelsie “Mob” Laszlo: Kelsie can channel and amplify the emotions of a crowd, syncing them into a single, euphoric mind. After the trauma of her father’s death and near destruction of a crowd, Kelsie seeks healing and stability through her bond with the Zeroes and through DJing. Her arc in Swarm explores her longing for connection and the fragile balance between empathy and control.

• Nate “Bellwether” Saldana: Nate is a natural-born leader, able to focus attention and rally people behind a cause. Charismatic and calculated, he sees the Zeroes as a movement. His need for control intensifies in Swarm, especially as new Zeroes emerge and the group’s secrecy is threatened.

• Chizara “Crash” Okeke: Chizara can manipulate electronics with her mind, crashing or controlling them. She is intensely private, valuing peace and control, and her connection to technology is both her strength and vulnerability. In Swarm, she begins to unravel under the pressures of power failure—both literal and metaphorical.

• Thibault “Anonymous” Garcia: Thibault is invisible to anyone who isn’t actively interacting with him. A loner by nature, he navigates the world through detachment. Yet, his deepening relationship with Flicker brings warmth and complexity to his arc, revealing a longing to be seen and remembered.

• Riley “Flicker” Smith: Born blind, Flicker can see through other people’s eyes. She uses this ability to navigate the world, often forming bonds through borrowed sight. Her relationship with Thibault highlights her search for stability and identity. In Swarm, her ability is tested when reality itself begins to blur under the influence of other Zeroes.

• Sonia “Sonic” Sonic: A determined blogger and conspiracy chaser, Sonia seeks the truth behind crowd phenomena. Although not a Zero, she is a significant threat to their anonymity and plays a key role in exposing and navigating the truth about new powered individuals.

• The Swarm (Nate and Tessa): A mysterious couple whose presence creates a powerful psychic connection that severs others’ bonds and sows confusion. Their powers mirror and distort those of the original Zeroes, representing a terrifying next stage of evolution. They serve as both a literal and thematic embodiment of chaos.

Theme

• Power and Control: Swarm questions the ethics of power—how it should be used, controlled, or restrained. Each Zero struggles with the consequences of wielding their ability, particularly when emotions run high or situations spiral out of control. The addition of the Swarm duo challenges the group’s moral boundaries and how far they are willing to go to protect their own.

• Identity and Self-Perception: Nearly every character wrestles with a dual identity—their public selves versus the people they are beneath their powers. Scam and Mob embody this tension most vividly, but the entire group faces crises of identity when their abilities isolate or redefine them.

• Belonging vs. Isolation: The Zeroes find strength in their found family, and their sanctuary—the underground nightclub Dish—is a metaphorical and literal safe space. The disruption caused by the Swarm pair exposes the fragility of that bond and the longing each character harbors for connection.

• Technology and Influence: From Crash’s war with electronics to Flicker’s hijacking of sight, technology is both a tool and a battleground. The Faraday cage enclosing the Dish is not just a plot device but a motif for the limits of control and the danger of intrusion.

• Chaos vs. Order: Bellwether’s meticulous orchestration of crowd dynamics contrasts with the anarchic emotional surges unleashed by Mob or the invasive spotlight of Sonia’s investigations. When the Swarm arrives, the balance shatters, and the theme of chaos overrunning order dominates the novel’s central conflict.

Writing Style and Tone

Scott Westerfeld, along with co-authors Margo Lanagan and Deborah Biancotti, continues their multi-perspective, present-tense narration, allowing readers deep interior access to each character while maintaining narrative momentum. Each chapter is anchored in a specific character’s voice, giving texture to their inner struggles and how they perceive the events unfolding around them. The style is kinetic and immediate, reflecting the charged nature of the characters’ powers and their youthful volatility.

The tone of Swarm is darker and more fraught than its predecessor. While the first book flirted with mischief and rebellion, Swarm descends into the murky consequences of unchecked power. There is a tense undercurrent running throughout—both from external threats and internal dissonance—as relationships fray and loyalties are tested. Yet, moments of wit, vulnerability, and teen banter keep the novel emotionally grounded. This juxtaposition of tension and intimacy is what gives Swarm its layered appeal.