move as fast as I can.

With the speed, accuracy and elegance of a sailfish – the fastest fish in the sea – I grab my heavy binding machine and wrench it off my desk.

Breathing laboriously, I somehow waddle down the stairs, past my parents and grandmother without being asked any questions and into the garden shed.

I hook it up to the electrics.

With absolute focus, I do a little Google research on my phone, write down some neat underlined notes and put together my Top Secret Plan in a beautifully bound black folder.

I add a few relevant stickers I had lying around, because presentation is always important.

And a few badly drawn sketches.

Then I glance at my watch, tuck the folder under my arm and crawl into the space inside the rhododendron bush outside my house.

Toby’s already in there: wearing skin-coloured knitted earmuffs shaped like pointed Star Trek ears.

Seriously: where does he go shopping?

“Reporting for duty and hitting on all eight,” he says, giving a sharp salute. “Took it on the heel and toe and used my noodle. This is going to be duck soup.”

I blink at him for a few seconds. “What?”

“I’m clammed after the dust out, eggs in the coffee. Ready for the flimflam. Grab a little air.”

He holds his hand up.

I stare at it. “Toby, don’t make me regret texting you.”

“It’s Detective Speak,” he says in surprise. “This is how they do it, Harriet. This way nobody but us knows what we’re talking about.”

“I don’t know what you’re talking about either.”

“That could be a problem,” he concedes. “So what’s the plan?”

I straighten my shoulders and proudly present the Top Secret folder with both hands.

“This,” I say solemnly. “It is a very important task, Toby Pilgrim.”

He takes it with an expression of reverence. “Have you discovered why tomatoes have more genes than humans, a subject that still baffles scientists to this day?”

“No,” I say with some certainty.

“Do you know where all the missing lithium in the Universe is, given that there’s only a third as much as we would expect there to be?”

“N-no.”

“Is this a folder containing information on why some nutrient-rich areas of the ocean have very little phytoplankton, otherwise known as the Antarctic Paradox, and you would like me to submit it to NATO anonymously?”

OK: he’s totally ruining my moment.

Mine’s not going to sound anywhere near as impressive now.

“No, Toby,” I snap slightly. Then I adopt my mysterious voice again. “Toby Pilgrim: this is your mission, should you choose to accept it. It is of utmost importance, time-sensitive and needs to be carefully handled while I’m in India on a modelling shoot.”

He nods in awe. “Copy that.”

“Follow it exactly,” I say cryptically. “It is delicate. Subtle. The complex intricacies are beyond the understanding of most mere mortals.”

“Will I understand it?”

“Probably not fully,” I admit enigmatically. “Just do what it tells you to and all will be well.”

“Harriet Manners,” Toby says in wonderment, “I am your man.” Then he starts laughing. “Not literally, obviously. Hahahaha. You can’t seduce me.”

I glare at him. “Are you going to take this seriously or not?”

“I am,” he says, straightening his face. “I will carry this out exactly as laid out in the oracle. I will die to defend it. Nobody will know.”

“Apart from Nat,” I say, thinking about it quickly. “You can tell Nat if you want.”

“Apart from Nat,” he repeats obediently.

“And India.” I think about it a bit more. “You can tell her too if you like.”

“And India,” he agrees.

“And if my dad asks then it’s all right if you want to—”

“Harriet,” Toby interrupts. “I don’t feel like you understand the words ‘Top Secret’.”

I nod: he has a valid point. “Repeat after me: I, Toby Pilgrim, will carry this project out perfectly in preparation for Harriet’s return in three days’ time, at which point she will take over.”

“Two days.”

“Sorry?”

“You come back in two days and three hours. It’s a surprisingly short trip.”

It’s at times like this I remember quite how good at stalking Toby is.

“Just say it, Toby,” I sigh.

He makes the oath, slides the folder with great respect into his rucksack and I feel a weight lift off my shoulders. A weight I didn’t really notice was so considerable until it was gone. I can leave now, knowing that everything is perfectly in place.

“Pipe that,” Toby says, crawling out of the bush with a cautious and unnecessarily elaborate look each way. “All silk so far. Scram out.”

I crawl out too and we high-five each other.

Then I run back to the shed and drag my binding machine out to lug up to my room again.

And by the time Rin wakes up, forty-five minutes later, it’s as if I was never gone.

I am a plan-making ninja.

She will never suspect a thing.