What if you spent your first 16 years so close to someone you shared a heart? What would you think if they came to you 10 years later, covered in someone else’s blood? What would you risk to save your twin sister?

Taema is the quiet twin, an ambitious engineer who has left behind her isolated, tech-averse upbringing to help design innovative green energy generators. Tila is her extrovert sister, a hostess at an upper class club, paid to share Zeal-fueled dreams with the rich. 

Born conjoined in a Californian cult, they escaped to survive and have made their separate lives in a near-future San Francisco where the crime rate is artificially low and poverty is obsolete. It could be utopian, but it’s clear from the start that the city is rigidly controlled by the government and the pharmaceutical industry. Zeal allows you to express all your urges (yes, you’d be right to read sex and violence into that subtext) in the safety of your dreams, and its soporific after effects have successfully reduced the murder rate to zero.

For the average citizen, Zeal is an occasional escape. For the unlucky few, it’s an irresistible addiction. For Taema and Tila, it’s unnecessary – their cult upbringing left them immune. Lucid dreamers, Zeal has nothing to offer them (except, in Tila’s case, a pay cheque).

But this is San Francisco, where there’s always someone on the look out for a disruptive idea. The Ratel, a violent crime syndicate that clearly isn’t included in the official zero-murder statistic, are contaminating Zeal with a new drug called Verve, which enhances violent instincts and has no peaceful comedown. 

When Tila is arrested for murder, Taema’s world is turned upside down. Discovering her twin was active in the Ratel is a second blow; how well does she really know the woman she once shared a heart with? Agreeing to go undercover to clear Tila’s name is the only way to save her twin from stasis and discover exactly what she’s been up to. 

And honestly? I haven’t scratched the surface of the ideas or the world building in play here. Every précis sounds like Lam threw in the kitchen sink, but this is one of those accomplished novels that harnesses its ideas tightly to deliver a taut, thrilling ride that never overwhelms (or loses track of) itself or the reader. 

Told half in a nail-biting first person present by Taema and half in reflective journal entries as Tila describes their childhood from her cell, the narrative is always as much about the twins’ relationship as their circumstances. It’s this intimacy that engaged me from the very first paragraph, and kept me compulsively turning the pages as the plot spilled over. 

I strongly recommend starting this book when you’ve got a nice clear day ahead so that it won’t matter if you refuse to put it down again. This is the first book to swallow me whole since Carey’s The Girl With All The Gifts; I started it at bedtime on a school night and had to force myself to set it aside in the wee hours. Don’t be me. Get in early and cancel all your appointments.

*****