‘What was that?’ asked Friday.

  ‘A power outage,’ said Ms Dekker.

  ‘Caused by what?’ asked Friday.

  ‘Caused by someone pouring a sink full of water in the bathroom and throwing an electric toaster into it,’ said Ms Dekker.

  ‘That would do it,’ said Friday.

  ‘You can’t prove that was Brad,’ said Halley. ‘All toasters look alike.’

  ‘This toaster had the words “Property of Dr Bradley Chowdhury” etched into it using a laser cutter,’ said Ms Dekker. ‘I know his office has one of those too.’

  ‘I see,’ said Friday. ‘That is suspicious.’

  ‘Then there’s the CCTV of Dr Chowdhury walking across campus carrying his toaster as he approached this building,’ said Ms Dekker.

  ‘Oh,’ said Halley. ‘I didn’t know you had that.’

  Ms Dekker opened another CCTV file and showed them footage of an attractive athletic-looking, dark-skinned man walking up the path carrying a toaster under his arm and what looked like a small suitcase in the other.

  ‘He’s a looker,’ said Melanie. She smiled at Halley. ‘Well done, you.’

  ‘Thank you,’ said Halley. It was a serious situation, but she allowed herself a small smirk of pride.

  ‘There he is entering the building at eleven fifty-five,’ continued Ms Dekker. She fast forwarded through the footage again. ‘And here he is, eight minutes later, leaving.’ They watched the footage as Brad burst out of the building and ran away, now only carrying the suitcase. ‘This is more than enough grounds to suspend Dr Chowdhury indefinitely.’

  ‘I disagree,’ said Friday. ‘You have compelling evidence that Brad broke into this building last night. And he did commit a crime. But I can prove he didn’t commit the crime of the substitute toothbrushes.’

  ‘You can?’ said Halley.

  ‘How?’ asked Ms Dekker. ‘Are you going to claim it was digital editing? That is the type of thing these nerds would do. But not in such a short time frame.’

  ‘No, the solution is much more simple than that,’ said Friday. ‘You’re too used to dealing with these physicists. They spend all day thinking about complicated problems and even more complicated solutions. This crime couldn’t be more simple.’

  ‘What do you mean?’ asked Ms Dekker. ‘We’ve analysed the CCTV footage, we’ve found the equipment logs and we’ve got this inter-departmental childish behaviour. It’s all there.’

  ‘It’s all there, except for the cans,’ said Friday.

  ‘What are you talking about?’ asked Ms Dekker.

  ‘If Brad emptied out a full vending machine,’ said Friday. ‘That would be over a hundred cans of soft drink. Where did they go?’

  ‘In the suitcase he brought with him,’ said Ms Dekker.

  Friday rewound the footage to show Brad running back along the path. ‘A hundred cans of soft drink would weigh over thirty kilos. He wouldn’t be able to run that fast. And they wouldn’t fit into a case that small.’

  ‘Just because he’s a nerd doesn’t mean he’s not fit,’ said Ms Dekker. ‘Nerds don’t have real social lives, they often spend all their free time lifting at the gym.’

  ‘Okay, but there is no explanation for the eight minutes,’ said Friday. ‘I agree it is possible to steal the contents of a vending machine using an endoscope. But that would take hours. A can of soft drink is circular and slippery. It would be hard to grip and manoeuvre. Each can would take at least a minute. Longer if it was at the back of a rack. To get out a hundred cans would be a painstaking process.’

  ‘My aunt had her gall bladder out and the surgery took two hours,’ said Melanie. ‘And that was just one gall bladder. And a gall bladder is squishy and easy to grab hold of.’

  ‘But if it wasn’t Dr Chowdhury,’ said Ms Dekker. ‘Then who did do it?’

  ‘I don’t know her name,’ said Friday. ‘But we know what she looks like.’ She rewound back to the beginning when the sales rep was filling the machine. There’s your culprit.’

  ‘The rep?’ said Ms Dekker.

  ‘There are two ways to access this machine without damaging the door,’ said Friday. ‘You could use an endoscope to surgically access the machine through the chute. Or you could just open the door with the key. And she has got a key.’

  ‘But it’s her job to put soft drink in,’ said Ms Dekker. ‘She’s got no motive.’

  ‘You said that there had been repeated complaints when the vending machine ran out,’ said Friday. ‘There’s your motive. Who had to make a special trip over here every time there was a complaint? That sales rep.’

  ‘But she’d lose her job,’ said Ms Dekker.

  ‘Some things are worth losing your job for,’ said Friday. ‘My guess is this person was planning to quit anyway, and this was their unfond farewell to the department.’

  ‘But what was Dr Chowdhury doing sneaking into the building last night?’ asked Ms Dekker.

  ‘I’ve got it!’ called Brad. They could hear him moving about inside the Detector. ‘I’m coming out.’

  They turned to see a very dirty man clamber out of the hatch. His face and hands were blackened with grease, but his teeth were bright white as he smiled a huge proud smile, while holding something tiny aloft in his hand.

  ‘What was it?’ asked Halley.

  ‘A feather,’ said Brad.

  ‘A feather?’ said Halley.

  Friday took the feather from his hand and looked at it closely. ‘Columba Livia. The common pigeon.’

  ‘How did that get in the collider?’ asked Melanie.

  ‘Probably another prank! Pigeon racing or something!’ said Ms Dekker.

  ‘Not my problem,’ said Brad, packing up his equipment. ‘I just saved the whole super collider from cataclysmic failure. I simply clean up the mess these theorists make. I don’t come up with theories myself.’

  ‘But that’s the second foreign object found inside the collider this month,’ said Ms Dekker. ‘The HERA team found a grape in the tunnel three weeks ago.’

  ‘Typical HERA team,’ scoffed Halley. ‘They probably had another drinks party in the tunnel.’

  ‘The HERA team has been having drinks parties in the tunnel?!’ exclaimed Ms Dekker.

  ‘Are you angry because that’s against protocol or because they didn’t invite you?’ asked Halley.

  Brad sniggered.

  ‘If you knew about it, you should have reported it,’ said Ms Dekker.

  ‘Yeah, I’m busy doing my own job,’ said Halley. ‘I don’t have time to do your job for you as well.’

  ‘Are we done here?’ asked Brad.

  ‘No,’ said Ms Dekker. ‘So you didn’t break into the vending machine. But you did still sneak into the offices last night. What were you doing?’

  Brad smirked. ‘Just taking my toaster for a walk.’

  ‘And your suitcase,’ observed Friday. ‘It’s an unusual shape for a suitcase. It’s more the size and shape of a pet carrier.’

  Brad looked less smirky and more petulant now.

  ‘If I were you, Ms Dekker,’ advised Friday. ‘I’d check the MINERVA team’s water coolers for wildlife.’

  Half an hour later a fully grown live lobster was found in the water cooler in the head of lab’s office at the MINERVA building. As punishment, Brad was given an official reprimand on his Human Resources file, but the discovery also completely exonerated him of the more serious accusation of sabotage.

  Friday was fast asleep when the phone rang. It was an old-fashioned telephone and, since they had very little furniture, the rattling sound of its analogue ring echoed around the sparsely decorated apartment. There was no way Friday’s mum would wake up to answer it. She seemed to permanently use earplugs. And Melanie could sleep through a tornado. Friday briefly considered ignoring it herself, but then her brain started to wake up and the thought occurred to her that it could be Uncle Bernie ringing with information about Ian . . . then another thought occurred to her – it could be Ian! She scrambled out of bed and hurried to the phone.

  ‘Hello,’ she said hoarsely.

  ‘Good, it’s you,’ said the voice on the other end.

  ‘Ms Dekker?’ asked Friday, she glanced at her watch. ‘Why are you ringing me at six-thirty in the morning?’

  ‘He’s coming today,’ said Ms Dekker.

  ‘Who?’ said Friday.

  ‘The new admin honcho,’ said Ms Dekker. ‘Dr Gregor Dalecki. He’s surprising us by arriving a week early.’

  ‘Why?’ asked Friday.

  ‘It’s brilliant,’ said Ms Dekker. ‘We don’t have enough time to clean up any mess now. He’s trying to catch us off guard. Well, I’m not letting that happen.’

  ‘Okay,’ said Friday. She still wasn’t entirely awake and this conversation was not making much sense. ‘But why are you calling here so early in the morning?’

  ‘Because there will be a formal welcoming ceremony in the auditorium today at twelve noon to introduce Dr Dalecki to the staff,’ said Ms Dekker. ‘You need to make sure your mother is there.’

  ‘She won’t like that,’ said Friday.

  ‘I don’t care,’ said Ms Dekker. ‘Dr Dalecki will expect to meet all the Nobel Laureates on staff. We have to make a good first impression or he’ll start rolling out the latest management strategies. Anything new always upsets the scientists. Then they’ll start acting out. Then my life will be a nightmare.’

  ‘I see,’ said Friday. She really could envisage all that.

  ‘Just make sure she’s there,’ said Ms Dekker.

  ‘I will,’ said Friday.

  ‘And that she’s on her best behaviour,’ added Ms Dekker.

  ‘That I can’t promise,’ said Friday.

  Five and a half hours later, Friday had a firm grip of her mother’s arm as she led her towards the auditorium. Dr Barnes was actually looking quite spry. Melanie had brushed her hair while she was arguing with Friday, and they’d made her put her good cardigan on, the one with the least number of holes in it. Dr Barnes had reluctantly agreed to attend the event so long as she was allowed to take her notebook and wear earplugs so she could keep working during the inevitable boring speeches.

  Friday deposited her mother in her allocated seat up on the stage. Dr Barnes was literally being used as a prop. CERN might have three Nobel Laureates on staff, but they had only one female Nobel Laureate, and the PR team wanted to make sure she was in the background of any photographs. Dr Barnes was positioned to sit right behind and to the right of anyone who was speaking at the podium. Friday prayed her mother didn’t do anything embarrassing – like pick her nose or rush out of the auditorium in search of a computer because she’d suddenly had an idea about leptons. Ms Dekker was sitting directly behind Dr Barnes to keep an eye on her.

  Friday and Melanie went down into the main part of the auditorium to find themselves seats up the back. The hall was filling up. A lot of threatening emails must have been sent to department heads. Friday couldn’t imagine that this number of scientists would take time away from their work voluntarily.

  ‘This is like being back at school,’ said Melanie.

  ‘Yes,’ agreed Friday. Obviously, the staff were adults, but most of them were still attached to universities. They had never really left school. They still slouched around and goofed off like students.

  Someone slid into the seat next to Friday. She was surprised to see it was Quantum. It was an unexpectedly friendly thing for him to do, to seek her out.

  ‘Hello,’ said Quantum. He looked a little nervous. He probably didn’t like being away from his work. He kept rubbing his hands nervously.

  ‘You couldn’t get out of this either?’ asked Friday.

  ‘No,’ said Quantum. ‘The head of lab locked the front door of our building. We couldn’t get inside our offices, and it’s cold outside so we had to come here.’

  ‘I brought a bag of earplugs for Mum,’ said Friday. ‘I can give you two if you want.’

  ‘Nah, I’m good,’ said Quantum. ‘I’m impressed you got her here on time and looking very professorial.’

  ‘That was mainly Melanie,’ said Friday. ‘She’s better at passive bullying than me.’

  ‘It’s a gift,’ said Melanie.

  ‘Is Marika here?’ asked Quantum.

  ‘Who?’ asked Friday.

  ‘Marika Dekker, the lawyer,’ said Quantum.

  ‘Oh,’ said Friday. ‘I didn’t know her first name. She’s the type of person I don’t think of as having a first name.’

  ‘Can I have your attention?’ A voice boomed out over the auditorium. Friday looked up to see a man in a suit and tie standing at the lectern. The crowd kept talking amongst themselves and ignoring him.

  ‘Who’s that?’ asked Friday.

  ‘Dr Ballentine,’ said Quantum. ‘He’s the Chief Scientist here at CERN.’

  The Chief Scientist tapped the microphone several times as if to check it was on. It clearly was because it made a deafening sound every time he hit it. He was just getting everyone’s attention. ‘Thank you,’ he said peevishly. ‘Dr Dalecki’s car has just pulled up outside the building. He will be here in a few moments. Before he arrives, I want to have a few quick words with you all.’ He paused and glared at everyone in the room for dramatic emphasis. It was impressive. It is hard to stare down a room of a thousand people, but he did a good job. ‘Behave!’ boomed the Chief Scientist. Several people flinched. The PA system squealed. ‘Behave as though your jobs and your research grants depend on it, because they do.’

  He let those words sink in for a moment as he adjusted his notes. He glanced off stage and nodded to someone in the wings. ‘Ladies and gentleman, esteemed scientists, it gives me great pleasure to introduce to you the new administrative head of CERN. Dr Dalecki has in his illustrious career administered some of the finest research institutes in Europe including Ultrecht University of the Netherlands and the University of Munich . . .’

  Quantum made a scoffing noise and whispered under his breath to Friday, ‘The University of Munich! That’s practically a polytechnic.’

  ‘Please make him welcome here to CERN, Dr Dalecki!’ announced Dr Ballentine, holding out his hand like a game-show hostess.

  Dr Dalecki strode out on stage. He was about fifty years old, with grey hair, but he was very well groomed. His clothes were perfectly pressed and not a hair was out of place.

  ‘Urgh,’ groaned Quantum. ‘He even looks like a used-car salesman.’

  ‘I like your brother,’ said Melanie. ‘He’s surprisingly catty.’

  ‘Thank you, Dr Ballentine,’ said Dr Dalecki. ‘I’m honoured to take on this role. Cutting-edge science will always pose unforeseeable organisational challenges. I look forward to lending my expertise in our journey to overcome these obstacles. It has been brought to my attention that there have been some human-resources issues recently that have hindered the research here at CERN.’

  There was muttering amongst the audience now.

  ‘Science is collaborative,’ said Dr Dalecki. ‘Inter-team rivalry and jealousy will not be tolerated.’

  He glared sternly at the room. Everyone fell silent. Then Dr Dalecki smiled. But it was not a warm smile. ‘We are all going to get along and work collaboratively together for the advance of science and, therefore, the world. We are all friends here. And if we are not now. We need to learn to be. That is why, my first act in my new role here at CERN will be to hold a community-building exercise.’

  This got everyone’s attention.

  ‘Please say it involves food,’ muttered Quantum hopefully.

  ‘We are going to have a sports day,’ said Dr Dalecki.

  Everyone in the room groaned.

  ‘I thought you would feel that way,’ said Dr Dalecki. ‘I know science nerds aren’t normally the sporty sort, but sporting games are a much better way to express competitive instincts. So let’s play, burn off those competitive energies and then get back to doing our work collaboratively. I want this to be fun. So I asked myself, what sort of sport would scientists enjoy? My first thought was Dungeons and Dragons . . .’

  Several people in the audience cheered, then stopped cheering when they realised they were not in the majority.

  ‘But Dungeons and Dragons is not a very good spectator sport,’ continued Dr Dalecki. ‘So then I had a better idea – robot wars!’

  Now there really were cheers and whoops of delight from the crowd.

  ‘You’ve got three days to build your robots,’ he said. ‘Every research team must enter one. Then on Saturday we’ll pit them against each other. I’m told the on-campus leisure centre has a suitable venue. And I will even provide a barbecue – I know how you scientists hate paying for your own food.’

  There was more cheering for that announcement.

  Suddenly the back double doors of the auditorium bashed open. Friday noticed immediately because they were sitting close by. But there was so much noise in the auditorium that few other people noticed, until the usher who’d burst in started shouting to get everyone’s attention. ‘Stop! Stop!’ he cried.

  The people around him fell silent. From up on the stage, Dr Dalecki could see his frantic efforts to get attention. ‘What’s going on?’ he asked through the microphone.

  Everyone was quiet now.

  The breathless usher called out, ‘It’s the equation! The equation has been vandalised!’

  ‘What?’ said Dr Dalecki.

  ‘Someone has scrawled graffiti all over the standard equation!’ yelled the usher.

  There was a hushed silence, then everybody in the auditorium started babbling at once.

  ‘Come on,’ said Friday.

  ‘Where are we going?’ asked Melanie.

  ‘To investigate the crime,’ said Friday.

  Moments later, Friday’s nose was about one centimetre from the blackboard as she peered at the equation. Dr Dalecki pushed his way through the crowd to see for himself.

  ‘Out of the way, let me through,’ he demanded, and the crowd melted back. When he got to the blackboard, his view was obstructed by the peroxide blonde hair on the back of Friday’s head. ‘Stand back,’ he ordered.