Now I understood why Lionel had looked at his stomach before, and why he had stared up at the ceiling. He hadn’t been thinking about the painting – he had been thinking about the café, and food. This is why it’s very hard to deduce what people are imagining just by watching their bodies and faces. So Lionel was not a suspect any more. We could rule him out.

  And that meant the only suspects left were Helen Wu and Lana, working as a team. By logical deduction we had solved the Guggenheim Mystery. So why did it still seem so unfinished? We did not know why they had hidden the screws and tools behind the false wall. We did not know where the painting was, or how it had been taken out of the museum. We were still confused.

  Salim’s phone beeped. ‘It’s Ty,’ he said. ‘The maintenance crew have been called back in.’

  Then Lionel’s walkie-talkie crackled. ‘Security, come in,’ said Sandra’s voice.

  ‘Security here,’ said Lionel. ‘What’s up?’

  ‘Go find the kids and tell them to get themselves an ice cream or something. I don’t want them here when the detective arrives.’

  ‘Sure, whatever you say,’ said Lionel. ‘I’m with them now. Got that, guys?’

  ‘Whatever,’ said Salim, shrugging.

  ‘They got that,’ said Lionel into his walkie-talkie.

  Salim took a picture of Lionel in the gift shop, the poster tubes behind him and his walkie-talkie in his hand. Then Lionel clipped the walkie-talkie back on his belt and put his arms round Salim.

  ‘It’ll be all right, kid,’ he said. ‘I promise.’

  But Salim pulled back from his hug. ‘Come on, Ted, Kat. Let’s go.’

  As we followed him out of the museum, my brainwaves were spinning. How could we solve the Guggenheim Mystery now?

  FORTY-EIGHT

  Out of the Blue

  We sat on the hot white steps of the Metropolitan Museum of Art, which is also on Fifth Avenue, and ate ice cream. I had another Magnum. I gave the chocolate to Kat, but she was eating something called a Creamsicle, which was bright orange and fizzy, and she waved my hand away. So I gave it to Salim. He was eating a Good Humor Bar, which I thought was a bad name, both for it and Salim. Salim was not in a good humour. He stared at the chocolate from my Magnum and let it melt down his fingers. I stared at it too, and thought.

  ‘We need to be logical,’ I said. ‘There are people we have ruled out. It can’t be Jacob, because he wasn’t in the museum on Monday to steal Aunt Gloria’s credit card. It can’t be Ty, for the same reason. It can’t be Sandra, because she is too small and couldn’t have carried the painting anywhere, and she couldn’t have smashed the frame with her high-heeled shoes. It can’t be Gabriel, because he didn’t have a pass for Aunt Gloria’s office, and also he was busy arguing with his friend. It can’t be Lionel, because he was committing a crime, but not the right crime. He is a thief of food, not a thief of art. Unless he was lying to us?’

  I said this because I was still not sure I knew when people were lying. Lionel’s guilt or innocence rested on the way he behaved, and that wasn’t something I could be certain I understood. I knew that I was sad at the thought that Lionel might be fired, but that wasn’t useful to my deductions.

  ‘He was telling the truth,’ said Salim. ‘I know it, just like I knew he was lying before. I know him.’

  ‘Hrumm,’ I said. ‘All right. We also know that it wasn’t Ben or Rafael, because they ran into each other very soon after the smoke started, and gave each other alibis. Rafael and Ben were also not at the museum on Monday. It wasn’t Hank, for the same reason. That leaves Helen and Lana. We know that Lana lied about being with Helen when the smoke happened. We know that Lana wasn’t at the Guggenheim when Aunt Gloria’s card was stolen, and she could not have called the removal companies either, but Helen could. We know that Lana needs money because of her father being ill, we know that Helen and Lana are friends and like working together, and we know that Helen does not like Aunt Gloria, so wouldn’t mind framing her. We found things hidden in the Guggenheim near where they were working – which might be a clue to how they smuggled out the painting.’

  ‘That’s good, Ted. That’s really good! But if we just tell the police it’s them, they won’t believe us,’ said Salim.

  ‘They might!’ said Kat. ‘We’ve got lots of evidence!’

  ‘We haven’t,’ said Salim. ‘Because we still don’t know where the painting is or how they stole it.’

  Kat sighed and her lips turned down. ‘Unless we can show the police the painting and prove Auntie Glo didn’t steal it, then you’re right. None of it matters.’

  ‘Excuse me,’ said a lady from two steps above us.

  Kat took another bite of her Creamsicle. Orange fizz covered her lips.

  ‘Excuse me,’ said the lady. She was older than Mum – almost as old as the woman who had spoken to me on the subway, and I thought she looked like she might be Indian. Her thick silvery hair was cut short, and she was wearing a long blue dress that floated around her legs.

  Kat turned, and squinted up at her. ‘Hello?’ she said.

  ‘Hello,’ said the lady. ‘How old are you?’

  ‘Er,’ said Kat, wiping the fizz off her chin. ‘Sixteen. Why?’

  This was another of Kat’s lies. She is fourteen, and not even fourteen and a half: her birthday is on 15 March.

  ‘I love your shirt,’ said the lady. ‘Where did you get it?’

  Kat sat bolt upright. ‘I,’ she said, ‘I … I …’ Kat’s brain was suffering from a mini Ice Age. ‘I made it.’ And even though she had been Mean Kat about the Magnum crust, I decided that I would help her.

  ‘She designs clothes,’ I told the lady. ‘She’s trying to be discovered. Are you here to discover her?’

  The lady laughed, even though I had not said anything that was funny.

  ‘I’m here to see the “Hidden in Plain Sight” exhibition,’ she said. ‘It’s new. But I seem to have found you as well. Funny how plans change. If you made that, then you have a real flair for clothing design. Are you hoping to study it?’

  ‘Yes, but Mum and Dad don’t think I should,’ said Kat.

  ‘But of course you should!’ said the lady. ‘Here – I’ll give you my card. You have your parents call me and I’ll tell them what’s what.’ She clicked open her silky purse and pulled out a white square with black words printed on it. She put this into Kat’s hand – Kat was still having trouble with her brain Ice Age – and nodded down at us all. ‘Now I must go. I’ll be late for my exhibition window. Good day!’

  And she went walking up the steps into the Metropolitan Museum of Art, her blue skirt blowing around her.

  ‘Oh,’ said Kat. ‘Oh. Oh. OH! LOOK!’

  I looked. It was still the same white square I had seen before.

  ‘Jas Singh,’ said Kat, her voice coming out of her mouth in a gasp. ‘House of Cyriax. Oh. She’s very, very – she’s very, very, very—’ And, without explaining what Jas Singh was, she burst into tears. ‘This is amazing. Out of the blue, like that!’

  This made sense, because the woman had been wearing a blue skirt. What didn’t make sense was that Kat was crying. Nothing bad had happened.

  ‘That’s the first positive thing we’ve heard all day,’ said Salim, and he took a melted bite of his Good Humor Bar. ‘All we’ve been hearing is what didn’t happen. The painting didn’t go out through the roof. It didn’t stay in the museum, or if it did, we don’t know where it is. No one saw it go out of the front or the back door, but one of those must be right. How are we supposed to know which one is true?’

  ‘Ted?’ said Kat, and she nudged me. ‘Now would be the time for you to have a brainwave.’

  I squeezed my eyes shut, so that the New York August afternoon blinked out and left me with just blue and red swirls in front of my eyes. Sometimes I like to pretend that the only part of the world that exists is the part that I can see. So I pretended that the whole world was swirls. Then I imagined that the swirls were
my brainwaves, and I could see them refracting back from the inside of my eyelids. Refraction is how white light becomes a rainbow. There is a rainbow in In the Black Square, and so it is a painting about light, even though Kandinsky had used no real light, only paint. If he had wanted to make a painting with actual light, he would have had to use a camera, the way Salim does.

  That was an interesting thought. I opened my eyes. All of New York rushed in – the yellow taxis and the grey street and the blue sky and the white steps, with shadows from the sun.

  ‘What do you think?’ asked Kat.

  ‘Hrumm,’ I said. ‘I need to look at Salim’s camera.’

  Salim pulled his camera round on his neck so we could see its little display window. Last time I had been with Salim he’d had a camera with film in it. Now he had a digital camera. Everything had changed.

  He began to click through the photographs he had taken over the last two days. I saw the case all over again through Salim’s eyes. His pictures made a record of what we had done, and who we had seen – but they were unique to Salim. If I had taken them, they would have been different. I liked that. Salim was an artist too.

  There was the picture of Billy on the pavement, Sarah in her office, Ty with his tools, Jacob outside the German bar, Helen and Lana with their tools in the garden, Sandra’s fridge, with Kat looking inside it, the empty Guggenheim with its lights off, Lionel in the gift shop next to the pile of posters …

  ‘Stop,’ I said. ‘Go back to Helen and Lana.’

  Salim flicked backwards. There was the picture of Helen and Lana again, in front of the water feature, their tools piled up on the ground. Hammers, wrenches, nails and washers and screws.

  ‘Look,’ I said. ‘Look!’

  ‘At what?’ said Kat. Her voice was sharp and loud. She didn’t see what I saw.

  ‘The tools,’ I said.

  Then Salim understood. ‘Ted!’ he said. ‘You’re right! They don’t need all those tools and fixings to mend a paving stone. It’s like all the extra things we found behind that wall. There were so many of them – not just washers and screws, but actual tools. What if they are taking extra tools and materials out of the museums they work at, to sell?’

  ‘Do tools cost lots of money?’ asked Kat.

  ‘Yes!’ said Salim. ‘Ty told me once. They’re so expensive. You have to get them ordered specially. What if Helen has been ordering extra, with the museums paying for them, and then selling them?’

  ‘That would be why Helen stayed in the museum for such a long time when the alarm went off!’ said Kat. ‘She was packing up the extra tools and hiding them so the police didn’t ask about them. And that’s why Lana lied for her, because she must be part of it. It’s just like Lionel and the food! But, hold on – if that’s what they were doing, then who stole the painting? Does that mean it was Hank and Ben? But – how did they get it out? Was it in Hank’s uniform? Are we missing something?’

  I thought about Lana, and Helen, and working together, and something finally clicked into place in my head.

  ‘No, we aren’t,’ I said. ‘We haven’t missed anything. We know everything we need to solve the case.’

  FORTY-NINE

  Brainwaves and Light Bulbs

  We had thought that there were pieces of the puzzle that we still had not found. We had assumed that someone had seen something that we did not know about, or that the thief had to have smuggled the painting out of the museum in a way that we could not imagine.

  But what if that was the wrong way of looking at the problem?

  What if we did know everything we needed to? What if we had seen everything?

  Sherlock Holmes, who was a great detective, even if he was made up, said in one of the stories about him, ‘Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.’ It was impossible for the painting to have been taken out through the skylight, because Gabriel hadn’t been there to collect it, and no one else had been seen climbing on the scaffolding. It was impossible for the painting to have been taken through the back door, because Billy hadn’t seen it happen. It was impossible for the painting to have been taken out of the front door, because we hadn’t seen it happen, and later, when the police were there, they hadn’t seen it either. So the only theory that was left—

  ‘The painting is still inside the Guggenheim,’ I said.

  ‘Don’t be stupid, Ted!’ said Kat.

  ‘I’m not being stupid!’ I said. ‘I’m eliminating impossible things. The thief could not have taken the painting out of the museum without someone seeing it, so it is almost certainly still inside. We just have to work out where it is, and how the thief is planning to take it out.’

  I closed my eyes again, put my hands over my ears and breathed deeply. I had to think. I twisted the Guggenheim and its ramp, its triangular staircases and its long banks of lights around in my head, circles within circles, just the way Frank Lloyd Wright had wanted. But the Guggenheim was not exactly the way Frank Lloyd Wright had imagined it. Things change, the way exhibitions at museums change, and people change and have ambitions.

  I thought about voices, and telephone lines, and text messages. I thought about hiding paintings, and smoke bombs, and tools. I thought about the lights in Times Square, their patterns in the sky, and all the hands I had imagined. I thought that when people say the Guggenheim, they mean the big central space with the ramp, but it is really more complicated than that. It has stairs and tower galleries and gift shops and offices.

  Then I thought about all the things we had seen on our quest around New York. I thought about Effortless Light Removals. I thought about photographs and paintings, what was worthless and what was priceless, and how different those two things had turned out to be. I thought about figures of speech, and people using language precisely but also saying things they did not exactly mean. I thought about all the people I had met who were similar to me, even though I had been worried that they would be different. I thought about families, and friends, and people working together. I thought about outsides, and insides, and all the surprising things we had discovered about people: Ty and his ambition to become an architect, Lionel and his children, Jacob and his oompah music, Sandra’s gluten allergy and the Pop Tarts in her cupboards. I thought about Detective Leigh and how he moved his arms and legs stiffly, like I do. There was one other person who had moved stiffly, I thought – but at first I could not remember who. Then I thought of green leaves and blue sky, and I knew where the memory came from. Dad has taught me that another way of saying brainwave is light-bulb moment. I imagined a light bulb switching on, and I knew the one other person we had met in New York who would enjoy a visual pun like that.

  And I knew the answer to the Guggenheim Mystery.

  FIFTY

  The Guggenheim Solution

  ‘I know who took the painting,’ I told Kat and Salim. ‘I know why, and I know how, and I know how they are going to try to get it out of the Guggenheim.’

  ‘You don’t!’ gasped Kat.

  ‘I do!’ I said. Although I am learning how to lie, I wouldn’t lie about something important like this.

  ‘OH MY LORD!’ shrieked Kat. Her arms shot up into the air and the sparkles on her shirt glittered.

  ‘You’re not making it up?’ asked Salim. His face was still not sure. ‘You really know? How?’

  ‘Because of Pop Tarts and ice cream and building plans,’ I said. ‘Because of ladders, and all the hands in Times Square. Because of the way The Scream is not a painting of a scream – it’s a painting of someone hearing a scream. It’s the other way round from how you think it is at first, and that’s exactly what happened with this theft. We thought the painting was outside, when it was really inside. We thought that it had already been stolen, but it hasn’t actually been stolen yet. We have to hurry! We have to go back to the Guggenheim and prove that the thief is not Aunt Gloria.’

  ‘What? Of course it’s been stolen!’ said Salim.

&n
bsp; ‘Come on, Salim. Let Ted show us!’ shouted Kat.

  And then all three of us were running back up Fifth Avenue, back towards the Guggenheim.

  The skin on my arms and neck itched. My lungs felt small. My shoes hit the pavement, and the heat from it spread up through the plastic underneath them and the cotton of my socks into the soles of my feet and made them sweat. But I made myself concentrate. I had to be a hero like Odysseus, for Salim, and Aunt Gloria, and Kat, and also myself, because I could be a person who came to a new place and learned its pattern. I could change my plans, and still be Ted Spark.

  I saw the blue-and-white banners, and the silver-and-blue scaffolding that was now the Guggenheim’s exoskeleton. The white outside it had become an inside, and the first time I saw it I should have realized that even something that seems so clean and smooth has layers. The Guggenheim has been added to since 1959. It has a gift shop and a tower. It has been repainted and rewired and reorganized, and the thief knew that, and had used it to hide the painting in plain sight. They had taken Frank Lloyd Wright’s circles and triangles and used them to commit a crime.

  I went straight in through the revolving front door of the museum, past the shiny metal plaque on the floor that said LET EACH MAN EXERCISE THE ART HE KNOWS. That also made me sad, because I knew that the thief had done exactly that. They had used what they knew to trick us all, and frame Aunt Gloria.

  Inside, the maintenance crew were working again, the noise from their voices and their tools bouncing off the white walls. Helen and Lana were at work on another false wall, their tool bag between them. Jacob was polishing the floor. Ben was drilling holes for paintings. I couldn’t see Ty.

  Lionel saw us. ‘Hey!’ he said. ‘What are you doing back already?’

  ‘Salim left his wallet in the gift shop,’ I said. This was my eighth lie.

  Salim and Kat looked at me. I saw the corners of Kat’s mouth twitch. ‘Yeah,’ said Salim. ‘My mistake. Can we just—’