In the post room, Sophie greeted Ellie with her usual grin, but it soon faded when she saw the expression on Ellie’s face.

“Whatever’s the matter?”

Ellie skirted round a huge cardboard box that had been delivered from a famous fashion designer and dodged behind Sophie’s desk. She slumped down at the table and pushed aside a pile of post that Sophie had been sorting.

“I thought I was coming to a brilliant place to do my work experience, but it’s a madhouse!”

Sophie grabbed the biscuits and put them in front of Ellie. Ellie took one and bit into it, speaking through the crumbs. “I tried really hard to be objective, but it’s impossible to discover what’s going on. I’m sure you and Flynn aren’t responsible, but I can’t work out who is! I thought it was Piano for a while, but she’s gone all hysterical, and then I began to wonder if Francesca had some sort of vendetta going on because of not getting Angel’s job like you said, but she’s been quite nice to me.”

“Whoa there, Ellie.” Sophie switched the kettle on and rescued the post from Ellie. She finished sorting it quickly and sat down opposite her. “Where’s your evidence? I think you’d better start from the beginning, and if you’re thinking of accusing me or Flynn of something you’d better stop eating my biscuits.” Sophie sounded annoyed.

“Sorry.” Ellie pushed the packet away.

“It’s all right. I can see you’re in a state.” Sophie pushed the packet back after taking one herself. “Start at the beginning and tell me everything.”

Ellie did, from her altered article to the problems with the water delivery, the missed photo shoot and then today’s dramatic events. “Look at my hands!” said Ellie, putting her biscuit down and showing Sophie her blackened fingers. “I’ve been set up. How can I prove I didn’t mess up Angel’s office looking like this?”

“You told me Francesca sent you into Angel’s office,” Sophie said.

Ellie looked stricken. “Yes. Which might mean she’s setting me up, but I can’t believe it!”

“I think you need to go and wash your hands and calm down,” said Sophie. “Go on. I’ll still be here when you get back.”

Ellie did as Sophie suggested, and she did feel a bit better after scrubbing the black marks off her hands. But as she rejoined Sophie, another thought hit her. “Francesca said she didn’t need my ‘help’,” she told Sophie, “when I was trying to suggest that someone had it in for the magazine.” She looked at Sophie, feeling stricken. “I don’t want it to be Francesca, but I’m getting very afraid that it might be.”

Sophie sighed. “You have to be totally certain of your facts before you accuse anyone.” She pondered for a minute and then reached for her mobile. “I’m going to text Flynn. This needs more than two brains to work it out.”

“It’s no good,” said Ellie gloomily. “He’s going to be up there for ages sorting out the IT problems for them.”

“Well until he comes we’ll just have to do the best we can without him,” said Sophie.

But it wasn’t too long before Flynn arrived. The problems hadn’t been too difficult to sort out. “Someone had changed all the fonts the magazine uses to Wingdings: you know,” said Flynn, “that font with all the meaningless squiggles. Piano had panicked, pressed a few wrong buttons and then panicked even more, but I soon got it sorted out for them. The formatting was all right really. Sometimes it can go a bit weird for no apparent reason. That and the Wingdings thing had them really spooked, but it’s okay now.”

Sophie opened a new packet of biscuits. “I’ll buy the next lot,” said Ellie.

“So…” Flynn took the mug of coffee Sophie offered him and sat down. “What’s your problem, Ellie?”

“I know I didn’t do any of this stuff,” Ellie said, after explaining everything. “But it all started happening since I arrived, and I’m sure they all think it’s my fault.” She sighed. “I suppose it doesn’t matter in one way because I’ll be out of here in a few days, but Uncle Patrick will think I’m useless, and I don’t want him to think that. He’s just started to take an interest in me and Mum again, and he’s the only family we’ve got.”

Flynn frowned. “Well, I can’t believe you’ll be accused of everything, Ellie, but let’s go back to the first time something went wrong. Tell me in as much detail as you can remember what happened the day the shoot was cancelled.”

Ellie recounted the day as far as she could remember, up until the point when Francesca had asked her to find the number for the water company so she could cancel the order. Suddenly, Flynn stopped her. “Was that the first time you’d used the database to find a number?” he asked.

Ellie frowned. “Yes, but it’s not difficult, Flynn. I’m not stupid.”

Flynn smiled at her sympathetically. “Of course you’re not. I’m just looking at the problem from as many angles as I can. So you entered the phone number of the water company for Francesca, and handed her the phone. What if you did get the wrong number by mistake?”

“Hang on,” said Sophie. “If Francesca had got through to the wrong number she’d have known, wouldn’t she, as soon as she heard the other person on the line? I mean, most people say the name of the company, don’t they?”

“Yes,” said Ellie, considering, and trying to be fair. “But the office was manic. While she was dealing with Piano, and making the call, Carlotta butted in with an urgent message, and Francesca was trying to write an article too. I mean, she was seriously distracted.”

For a moment they were all silent, then Flynn spoke. “So if Francesca was distracted by the commotion, doesn’t that mean that you might have been too, and keyed the wrong number into the phone?”

“No way! Stop thinking it was me!” Ellie was certain. “Look, if I had a computer here I’d show you how I found the number on the database. I can even remember some of it. I think it had several sixes and twos in it. Numbers stick in my head really easily.”

Flynn bent down and picked up his laptop case. “I can get into the database from here,” he said, opening it up. “Let’s check it out.”

In no time he had the database up, and Ellie was searching for the number of the water company in the contacts section. “There!” She stabbed her finger at the screen. They all looked. Coolwater Company. There were indeed several sixes and twos in the number.

Flynn scratched his head. “That seems pretty clear.” He pulled his phone out of his pocket. “Let’s call it.” He keyed the number in and waited while it rang. When the call was answered his eyes widened.

“What is it?” hissed Sophie but he ignored her.

Ellie so wished she could hear what was being said.

Flynn cleared his throat. “Sorry,” he said into his phone. “What company did you say I’d got through to?” He listened again. “Coolblue Model Agency? I’m so sorry. I seem to have the wrong number.” He folded his phone and stared at the girls. “Did you hear that?”

Ellie had her hand to her mouth. “I’m sure that’s Sapphire’s agency. You know, the model whose appointment was accidentally cancelled. This is awful. It was my mistake! Francesca must have cancelled the model instead of the water!”

“Well it’s not your fault,” said Sophie. “It’s Francesca’s for allowing herself to be so distracted that she didn’t check who she was speaking to – and we can blame the person who messed up inputting those numbers into the database too. Or maybe the file has become corrupted in some way.”

“Or maybe someone has corrupted it,” added Flynn, his fingers flying over the keys of his laptop. “No one could predict that messing up a few numbers in the database would lead to an important assignment being cancelled, that was just tremendous bad luck for Heart, but it’s the same sort of spitefulness as changing fonts and messing up your article, Ellie. I reckon that all this IT meddling has been done by the same person, and I know how to find out who it was!”

“I knew it was a good idea to get you involved,” said Sophie.

“You made up your own password to get into the computer system when you started here, didn’t you?” asked Flynn.

Ellie nodded. “I did it with you.”

“Of course. And you kept it secret?”

Ellie nodded again.

“Good. Everyone has their own password, which is secret, and as you log on, the system matches your username and the password. If they are correct it lets you in.”

“We know this!” said Sophie impatiently.

“But what you might not know,” said Flynn, “is that once you’re in, the computer logs every change you make in a transaction history, with the date and your name against it.”

“What if you use someone else’s computer?” asked Sophie.

“I was told to log out if I have to leave my desk,” said Ellie. “And I’ve seen the others do that too.”

“So even if the culprit used someone else’s computer she’d still have to log in, and the system would still know who she was. I know how to find that information but most people wouldn’t. What filename did you give your article, Ellie?” said Flynn.

Ellie told him and he keyed the name in on a page Ellie had never seen before. Soon, a long list of data came up on the black screen, with dates and names against each line.

“Look,” he said. “Every line of data shows a change that’s been made to your article.”

“Lots of the changes are mine!” said Ellie. “But then I wrote it.”

“But look here,” said Flynn. Suddenly there were loads of changes made on the same date by someone who wasn’t Ellie. She peered at the screen, but she couldn’t make sense of the data. She didn’t know anyone’s username except her own.

Flynn let out a low whistle and shook his head. “Well I never,” he said.

Ellie’s heart began to thump. “What?” she said. “I can’t understand it. Do you know who altered my article or not?”

“It’s there,” said Flynn, pointing to the username Ellie couldn’t identify. “Plain to see.”

“But I don’t know who glamgirl is!” wailed Ellie.

Flynn looked abashed. “Sorry,” he said. “I don’t know passwords, of course, but I do know everyone’s username. It’s Carlotta.”

“Carlotta!” Ellie was upset. “But she was okay about the interview,” she said. “She was jealous to begin with, but I thought she got over it and was fine. She wanted to know all about it afterwards. I thought it was Piano – she’s never liked me.”

Sophie was looking serious. “Can you check the other stuff?” she said.

“Of course,” said Flynn. “I’ll look at the fonts first.”

Ellie held her breath as he scrolled through and found the right files. It only took a few minutes to check. The fonts had been changed early that morning.

“Glamgirl,” said Sophie in a flat voice.

“But why?” said Ellie. “She’s got a job that loads of people would die for.”

Sophie shrugged and Flynn shook his head. He looked even more serious than he had before. “I ought to check the database now,” he said. “Of course lots of people alter bits of the database as information changes, but their usernames will be against every alteration. We can easily find out who last altered the water cooler information.” He worked away for a few minutes while the girls waited anxiously. When he found the file it didn’t come as a surprise to any of them.

“Carlotta again.”

“That’s it then,” said Sophie. “That’s plenty of proof for you, Ellie. No one can possibly blame you for anything now. She must have arrived at the office before anyone else, altered the fonts, and probably flooded the carpet and dropped something black and horrible all over Angel’s office as well. No question!”

Flynn was still looking serious. “What’s worrying me most though,” he said, “is how many other database entries she may have changed. It’ll take ages to trawl through all of the transaction history, and meanwhile the magazine probably has dodgy data to work with.” He closed the lid of his laptop. “The information will all need checking and putting right. It’ll take time and money, and meanwhile, other mistakes could be made. Ellie, I think you and I need to speak to Angel, right away.”