Their parents were spies. Their childhood was a training programme. Now Jake (16) and Maya (15) have to become the operatives their parents never wanted them to be — and the clock started yesterday.
Jake and Maya Mercer thought they knew their parents. Dad: a management consultant who travelled too much. Mum: a documentary photographer who came home smelling like airports and developing fluid. Normal. Boring, even.
Then their parents don't come home from Prague.
Then a woman named Helen appears at their door and tells them not to worry — which is when they start worrying.
Then they find the hidden safe behind the bookshelf. The fake passports. The cash in six currencies. The gun.
Then someone breaks into their house, and Maya puts him on the floor with a Krav Maga hold she learned at age eight — from an instructor her parents chose very, very carefully.
Their parents are spies. Their childhood was a training programme. The only way to get their family back is to become the operatives their parents never wanted them to be.
From a Prague rendezvous gone dark to a submerged ring of stones at the Mid-Atlantic Ridge — the Mercer twins follow MERIDIAN's trail across nine cities, nine months, nine increasingly impossible questions about what humanity used to know.
Each Mercer was raised on a different bedrock skill. The "family games" weren't games. The Friday-night silver-tray memory exercises weren't a hobby. By the time their parents disappear in Prague, Jake and Maya are already operatives. They just don't know it yet.
British black-budget intelligence cell. Four operatives, one analyst, no oversight. The Mercer parents were two of them. Helen Cross is what's left of the rest.
An older organisation, hunting older things. They believe a previous civilisation left an information network across nine sites. They're racing ONYX to find every node — and decide what humans get to remember.
A handheld electromagnetic-pulse device the size of a paperback. Disables cars, drones, alarms, comms. Plans surface in Berlin in Book Two. The auction in Istanbul was for a working prototype.
Nine sites. Nine continents. Cappadocia, the Amazon, Sigiriya, Samarkand, the Mid-Atlantic Ridge. Built by a civilisation that destroyed itself with its own technology — and left a warning.
The mole inside ONYX. Above Whitfield. Above suspicion. Unmasked at the Venice Biennale in Book Three. Probably someone the Mercer parents trusted with their lives.
Twelve objects on a silver tray. Thirty seconds to memorise. The Mercer kids thought it was a Friday-night ritual. It was eidetic-memory conditioning, and they passed every time.
Maya knew the man at the door wasn't a Jehovah's Witness because Jehovah's Witnesses don't carry guns under their left armpit. Their dad had told her that. Their dad had told her a lot of things.
"We're not buying anything," Jake said behind her, the way Mum had taught him — friendly, slightly bored, hand not visible. The way you talked to a stranger when you wanted them to think you were stupid.
The man smiled. The smile didn't reach the rest of him.
"I'm a friend of your parents," he said.
Maya was already moving. Eight years of Krav Maga since she was seven — karate, her parents had called it, like that wasn't suspicious enough on its own — and the hold she put him in took less than a second and a half.
The man hit the hallway floor like a sack of laundry.
"Jake," Maya said, calm, the way Mum was calm when the boiler exploded. "Get Helen."
"My fourteen-year-old finished it in a single sitting and immediately demanded to learn lockpicking. Mission accomplished."
A. ReyesYA Book Blogger · Toronto
"It's Alex Rider with a brain and CHERUB with a soul. Maya is the most quietly terrifying fifteen-year-old in YA right now."
The Quarterly PagePrint Review · Spring 2026
"Clayton writes spy tradecraft like a man who has either lived it or done worrying amounts of homework. Either way: read it."
Margaret HolmAuthor, The Cipher Girls
"The 'observation game' chapter is the most fun I've had in a YA novel in a decade. I'm absolutely going to do this with my kids."
R. PatelEducator · London
"Sharp, propulsive, and unexpectedly tender. The relationship between the siblings is the secret weapon."
Pre-Pub BuzzTrade Newsletter
"I have not been this annoyed at a cliffhanger since I was thirteen. Where is Book Two."
@spyfic_diariesBookstagram · 38k followers