When we get to school, trying to find out more about Curtis takes my mind off our most important gadget pick up. But finding out more about him is tricky. Curtis turns out to be as slippery as a Slush Puppie.

Sam tries to plant a tracker in his bag at morning break but it’s almost impossible because he never seems to put it down. ‘Bit suspicious, isn’t it?’ she says, as we stand to the side of the playground. ‘Never letting his bag out of sight?’

‘Yeah,’ I say. ‘And I think he’s changed his tactics too.’ I nod my head over to where Curtis is standing with Melissa and the rest of her girly girl gang. They’re all wearing feathery things in their hair. From this distance they look like a herd of My Little Ponies. Curtis is talking with them and, instead of looking upset, they’re laughing and nodding.

‘He’s trying to make friends instead of enemies now,’ Sam says. ‘That’s not good.’

‘Right.’ I watch as Melissa chats away to Curtis – what is she telling him? She only has to mention the boxer short incident (when the top of my boxers were seen in the changing rooms and Sam had to invent a new fashion craze) for my secret to be out.

‘Don’t worry,’ Sam says. ‘We’ll make sure we uncover him before he uncovers you.’

We’d better.

 

In the afternoon, Curtis asks to go to the loos. Five minutes after he comes back, the head of the school, Mrs Harrison, pops her head round the door.

‘Ms Hardy? Curtis has had a call from his mum – she forgot he has a dentist appointment this afternoon. He’s going to have to leave early – his mum will meet him by the school gates after lunch.’

Ms Hardy nods. ‘That’s fine. Thanks for letting me know. Curtis? Do you want to collect your things so you’re ready?’

Curtis gets up with a smug smile on his face. There is no way that anyone smiles like that when they’re on the way to the dentist. He must be up to something.

I quickly get out my infra-red pen and scribble a message to Sam.

‘I forgot to give you your pencil sharpener back,’ I say, pushing the note across to her, along with a pencil sharpener. ‘Pencil sharpener’ is our code for ‘urgent message’.

‘Thanks,’ Sam says. Then she pushes the pencil sharpener off the desk. ‘Oh dear, I’ve dropped it,’ she says and ducks under the table. We’ve agreed to keep our infra-red readers in our pockets so that we can pass messages anywhere and not worry about them being read or found. When Sam reappears after a few seconds she nods at me – she’s read my note and understood.

As soon as the bell goes we dash through the door after Curtis, who was the first one out.

It’s time to get Eyes On Curtis underway.

Outside in the playground, we spot him talking to Evie. By walking slowly beside them, we hear him asking her how long she’s played football, telling her that she’s good in goal and generally reversing his approach from being nasty to sickly sweet. I nudge Sam. It’s time for the Stumble and Slip plan. First I run towards Curtis, as if I’m on my way to see someone on the other side of the playground. Then I do the stumble – accidentally on purpose – that lands me (oops!) into Curtis’s side, knocking us both to the ground. Sam rushes over to help pick us up and in the process slips a tracker into Curtis’s bag.

‘Sorry about that,’ I say to Curtis. ‘Are you all right?’ I give him a Concerned and Caring Look but I don’t know how convincing it is because he just glares at me.

‘I’m fine,’ he says, brushing himself down. ‘Look where you’re going next time.’

‘Yeah, yeah, of course I will,’ I say. I don’t mention that I was looking where I was going – and I was right on target.

Sam and I both have the Sniffer Dog app on our phones from our last mission so now we’ll know exactly where Curtis is at all times.

‘It’s good we managed that before the Halloween party tomorrow night,’ Sam says, once we’re safely in the toilets. ‘Now if he is a mole, we can keep an eye on him.’

‘And see if he’s trying to keep an eye on us,’ I say. ‘Let’s find out what he’s up to now – because I don’t think it’s anything to do with the dentist. I’ll use the Voice Over and call the school office.’

Sam grins. ‘Go ahead – I’ve been dying to see it in action.’

‘Keep a look-out though – the last thing we need is for Melissa to come in and hear me sounding like Mum!’ While Sam opens the door a crack to peer through it, I dig down in my bag and bring out the Voice Over. I’ve been carrying it around ever since it dawned on me what I could use it for. I slip the necklace round my neck, pull out my phone and dial the school office. My heart thumps like a dog’s tail as the phone rings. I remind myself that if I want to sound like my mum I’m going to have to act like her. I straighten up as the secretary answers and frown at the phone the way I can imagine my mum doing.

‘Hello? This is Ms Marcus – Josie’s mum – I mean mother,’ I say, as sternly and confidently as I can. ‘Josie and Sam have an important doctor’s appointment today and will have to leave early – right now, in fact.’

‘They have doctor’s appointments at the same time?’ The school secretary sounds confused.

‘Yes, that’s right,’ I say, trying to make my voice clipped the way my mum does when she’s in business mode. ‘Sam’s mother is writing an important article and asked me to take Sam to the doctor’s with Josie.’ I take a breath. ‘I couldn’t call before now because I’ve been on very important business, and as a journalist, Sam’s mother is also obviously very, very busy.’ I hold my breath.

Sam’s staring at me in shock – I have to jerk my head at her to remind her to keep an eye on the door. I can’t blame her. It’s not often you hear your best friend sound exactly like their mother.

‘Well, all right, I’ll let their teacher know then,’ the secretary says slowly.

There’s a racket in the corridor – I can hear Melissa, Nerida and Suzy approaching. Sam jams her foot against the door so it can’t be opened. She hisses through it. ‘Toilet’s broken.’

There’s a babble of voices as Melissa and the others start asking questions. ‘What’s going on?’ ‘Are all the toilets broken?’ ‘I need a wee!’

‘Uh, Ms Marcus? Are you near the school now? I can hear children …’

I snap to. ‘Yes, that’s right. I’m near the school. Very near. So that I can pick up the girls.’

‘Oh, I see.’

‘Right, I’d better go then. Please make sure they’re ready straight away,’ I gabble into the phone before I hang up and shove the Voice Over necklace back in my bag.

Sam steps away from the door and Melissa falls in through it. ‘What’s going on?’ she says, looking around.

‘Nothing,’ Sam says. ‘We thought the toilets weren’t flushing but they’re fine now.’

‘Yeah,’ I say. ‘See?’ I run into one of the cubicles and flush the toilet. ‘Completely fine!’

Nerida stares at us. ‘You two are really weird sometimes, you know that?’

You have no idea how weird, Nerida. No idea.

 

Curtis leaves straight after the bell goes for the end of lunch so he doesn’t realise we’re leaving school too and won’t suspect we’re on his tail. We follow at a safe distance, using the Sniffer Dog app to trace his movements.

Curtis is either not really the mole or else he’s not a very good spy because he doesn’t use any of the skills Sam and I have been learning with my mum and dad. He doesn’t backtrack or change his appearance or even look behind him! If he’s training to be a real spy, whoever’s teaching him is doing a rubbish job. I think of Mum and Dad and all they’ve taught me. They might have put me in the worst disguises known to spy-kind, but at least I know that they’re teaching me the right skills to become a good spy.

Curtis heads to the leisure centre. We follow and watch him as he reaches the front doors and waits. We skirt the car park and hide behind a van parked in the road leading to the centre.

Sam pokes me in the ribs and whispers. ‘Fancy a ballet lesson for old times’ sake?’

‘Very funny.’ Just the thought of the tutu I had to wear in our last mission makes the hairs on the back of my neck stand up. Dan McGuire has been through some tough assignments – like when he had to get into a tank full of dangerous marine life in Dan McGuire and the Pesky Piranhas – but he never had to put on a dress or a tutu.

A black car draws up in front of Curtis and a man in a long coat gets out.

‘That’s the same man who was watching me and my dad at the garden centre!’ I say, standing up and stepping forward to get a closer look.

‘Do you think he’s trying to find out about your mum’s mission then?’ Sam says.

‘I don’t know,’ I say. ‘Maybe they’re trying to uncover me as a boy or maybe they’re trying to uncover Mum as a spy – but either way we have to make sure they don’t succeed.’

And right at that second, Curtis looks over in our direction. As I fling myself to the ground and roll away from the spot I was standing in I can’t help remembering Mum and Dad’s top spy motto – ‘attention, attention, attention’. This is my fault because I wasn’t paying any.

‘I don’t know if he saw me!’ I hiss. ‘We’ve got to get out of here – fast!’

Our last mission meant that we’d got to know the leisure centre inside and out and that comes in handy now. We slip round the building and in through one of the emergency exits to come out on the other side of the centre. I check the Sniffer Dog app.

‘It’s okay, he hasn’t tried to follow us,’ I tell Sam.

‘Maybe he’s getting instructions from that man,’ Sam says, her eyebrows drawing together in a worried frown. ‘But what if he did see you? I hope we haven’t made things more dangerous for your mum.’

Yeah, me too.

We sneak to a position where we can see the front of the centre from a different angle. The man is still talking to Curtis and we see Curtis nod several times before they both get in the car. The car pulls away. We watch the tracker on our Sniffer Dog app as the car disappears round the bend.

‘I guess that’s as far as we’re going to get today,’ Sam says. ‘But from what we’ve seen, it looks like we’ve definitely got to keep a watch on Curtis during the Halloween party.’

I nod, clicking on the Sniffer Dog app as the little blinking light shows the car getting further and further away.

The thing is, I don’t want to just watch out for Curtis, I want to catch him out too.