“Back to the master spy, you mean.” Harvey hunkered down on the branch and stared at Olive intently. “Listen to me. Do not trust him. Don’t believe anything he tells you. And don’t trust that woman he is staying with, either.”

  “Mrs. Dewey?”

  “She is not what she seems,” the cat whispered. “Neither of them is.”

  “Harvey, this is crazy. Come down right now and take your bath.”

  Harvey stared down at Olive for a moment. Then he bolted toward the trunk and clambered up into the higher branches.

  Olive rolled her eyes and turned back toward the house. Her book still lay open on the porch, but the breeze had moved its pages around, and she had completely lost her place. She didn’t feel like reading Sherlock Holmes right now anyway.

  She felt like reading something else.

  4

  THE LIBRARY WAS the biggest, dustiest room in the old stone house. It had a huge, tile-framed fireplace that looked as though it hadn’t been used in years, a painting of dancing girls in a meadow (who Olive knew for a fact were not as friendly as they looked), creaky rolling ladders reaching up to the ceilings, and battered velvet furniture with leaky stuffing trailing across the cushions like thick gray cobwebs. The library walls were lined with bookshelves that ran from the floor all the way up to the high ceilings, and every inch of the shelves was crammed with books. Olive guessed that it would take a person a hundred years to read all of them. Of course, that was just about how long Annabelle McMartin had lived.

  Most of the books were very old. They were bound with cloth or leather, and the gold-painted words on their spines were fading. Olive loved to read, but she didn’t love to read these sorts of books. They had titles like A Thoroughly Thorough and Exhaustive Exploration of the Fascinating Lives of Snails, and The Woeful Tale of a Maiden Who Went About without Her Tippet. Once Olive had taken down a book titled Wild Birds and How to Dress Them, thinking it might have some good suggestions for catching birds and making tiny costumes for them to wear, but the rest of the title, which couldn’t fit on the cover and had to be printed on the front page, was A Treatise on the Most Modern Methods of Plucking, Stuffing, and Basting Game Birds, Containing Sixty Handcolored Engravings of the Most Delightful Dishes Together with Invaluable Hints for the Home Cook. Olive had put the book back.

  Now she stood in the middle of the library and felt the dust tickling her nose. If the McMartins had left behind a book of spells—a grimoire, the boy had called it—then it made sense that it would be here, with all the other books. The memory of Rutherford Dewey’s eyes lighting up when she’d blurted those words—my house used to be owned by witches—made Olive’s whole body itch with embarrassment. Why had she said it? Why had she told him anything at all? Olive grabbed two fistfuls of her hair and yanked. Stupid, she told herself. Stupid, stupid, stupid.

  She glanced around the library. One important, secret book could easily blend in with thousands of others. A whole book full of the McMartins’ plans and spells could be right here, hiding in plain sight!

  The problem was where to begin.

  Olive knew that the books weren’t arranged in any particular order. They weren’t alphabetized or sorted by subject, like in school libraries. Books about plants nobody had ever heard of were next to books about politicians nobody had ever heard of, and with the print rubbing off of the covers, a person would have to open up most of the books to be sure of what was inside.

  Olive dragged the rolling ladder along the wall to the room’s right-hand corner. She climbed to its highest step, took a firm grip on the top shelf, and pulled down the very first book. A skin of dust smudged off on her fingers as she turned the book over. Lineage of the Russian Tsars, said the cover. Olive opened the book. A man wearing a hat that looked like a hairy cake stared back at her. There were no spells to be found here.

  The next book, Tales to Terrify Impudent Children, was a bit more interesting, but it wasn’t what Olive was looking for. Flipping through the pages of each book and sneezing every now and then, Olive made her way slowly to the end of the first shelf. She was thumbing through a copy of Truly Marvelous Advancements in the Manufacture of Canadian String when a voice from below nearly startled her off of the ladder.

  “What are you up to?” demanded Horatio as Olive wobbled and clutched the shelf for safety.

  “I’m just . . . looking,” said Olive.

  Horatio settled himself on the Oriental rug. “Yes, I suppose that’s what one usually does with a pair of eyes and a book,” he said. “Are you looking for anything in particular?”

  “Sort of,” she said slowly. “Horatio, did the McMartins have a . . . a grimoire? You know, some kind of book of spells?”

  Horatio looked up at Olive, his sharp green eyes scanning hers. “Why do you want to know that?”

  “Just out of curiosity.”

  Horatio blinked at her. “Olive, are you trying to kill me?”

  “What?”

  “You know: ‘Curiosity killed the cat.’ ”

  A little smile tugged at the corner of Olive’s mouth. “Horatio, are you making a joke?”

  Horatio gave a shrug that was almost bashful, and examined his toes.

  “So,” Olive wheedled, looking through her lowered eyelashes at the gigantic orange cat, “is there a grimoire somewhere?”

  Horatio sighed. He flopped over onto the rug, stretching his whole body into a furry orange parenthesis and then slowly spreading each individual paw. Bones realigned, he rolled into sphinx position and looked up at Olive. “There was a spellbook, yes,” he said, “although it was an incomplete record of the things the McMartins could do. Let’s just say that there are some types of magic that can’t be learned from a book. In any case, I haven’t seen the spellbook in more than seventy years. Aldous hid it, or Annabelle destroyed it, and either way, I doubt very much that you’ll find it.”

  Naturally, this made Olive want to find it even more.

  “But you cats were their assistants,” she argued. “Shouldn’t you know where something as important as their spellbook went?”

  “Precisely. We were their assistants. Things stopped being warm and friendly between the McMartins and the three of us long before the spellbook disappeared. Aldous could still force us to obey, but he didn’t trust us anymore.” Horatio turned away, padding a sunny patch of the rug with his paws. “And now, I would suggest that you listen to a wise old saying, and let sleeping cats lie.”

  “That’s dogs,” corrected Olive.

  Horatio, already in napping position, ignored her.

  Holding tightly to the ladder with one hand, Olive rolled along the wall to the next set of shelves and took down the first two books: A Tremendous Hullabaloo and Whatever Shall We Do About Hortense? Olive slumped on the step. Densely packed shelves surrounded her, covering the library walls from floor to ceiling. Even if the titles on the antique spines had been clear, the McMartins were certainly clever enough to hide a book of spells inside some misleading cover. Olive had done this herself sometimes. A paperback mystery fit very easily inside her math textbook.

  It had taken her about fifteen minutes to look through the books on one shelf. There were four sets of shelves along each short wall, and six shelves along the longer walls, spaced between two tall windows, the fireplace, and the painting of girls frolicking in a meadow. Each set of shelves had nine shelves within it. If she added and then multiplied the total number of shelves by the number of minutes she spent on one shelf . . . The numbers ran around inside Olive’s head and smashed into each other like a bunch of blind football players. It would take her a very long time.

  She pulled down the next book, inhaled a puff of dust, and sneezed until she could see spots.

  “That’s one good thing about you, Olive,” murmured Horatio from the rug far below. “You’re not a quitter.”

  Olive rubbed her itchy nose and got back to work.

  The sun was casting peach-colored trails through the library wi
ndows when Mr. Dunwoody strolled in, whistling “Inchworm” cheerily to himself. “Inchworm” was Mr. and Mrs. Dunwoody’s special song. They had danced to it at their wedding, and in fact were probably dancing to it in the photo that sat on Mr. Dunwoody’s desk, in which a younger Alec and Alice beamed at each other in the middle of a tiny dance floor, romantic light reflecting off of the lenses of their large round glasses. These days, Mrs. Dunwoody wore contacts.

  Mr. Dunwoody settled himself in the chair at his desk. Horatio made a beeline out of the room.

  “I don’t think that cat likes me,” said Mr. Dunwoody.

  “He doesn’t dislike you,” said Olive, perched like a bookish spider in one high corner. “He’s just sort of. . . reserved.”

  Mr. Dunwoody looked up, startled. “Oh, hello, Olive. I didn’t know you were in here.”

  “Then who were you talking to?”

  Mr. Dunwoody stared thoughtfully up at the ceiling. “That’s a valid question.”

  Olive blew a bit of dust off of her fingers. “Dad, about how many books do you think are in this room?”

  “A rough estimate?” Mr. Dunwoody scanned the walls. “Twenty shelving units, nine shelves on each, and an average of forty-five books per shelf? Eight thousand one hundred books, give or take.”

  Olive ran her fingertip across a row of battered spines as if she were playing a mute piano. “What if a person spent thirty seconds looking at each book, just flipping through the pages? How long would it take to look at all of them?”

  Mr. Dunwoody tilted happily back in his chair. “Thirty seconds per book equals 243,000 seconds, equivalent to 4,050 minutes, or to 67.5 hours.”

  “That’s what I thought,” said Olive. “A very long time.”

  “A ‘long time’ is relative,” said Mr. Dunwoody. “Time itself is relative.”

  Olive, who had been told this sort of thing as frequently as other children are told to brush their teeth, nodded obediently. “Well, do you think it’s almost time for dinner, here and now, in real-world time?”

  Mr. Dunwoody sniffed the air. “Judging by the scent coming from the kitchen, I would say yes.”

  “Good.” Olive climbed stiffly down the ladder, feeling sore in more ways than one. She was probably no closer to finding the book she was looking for, and even worse, the memory of her own voice blurting out “My house used to be owned by witches!”—to a complete stranger—made her flush with fury at herself every time she relived it. Why on earth had she told that boy her biggest secret?

  “Dad,” said Olive as she and her father walked down the hall toward the lovely smell of lasagna, “if you told somebody a secret, and you weren’t sure you could trust that person to keep it a secret, what would you do?”

  “Hmm,” said Mr. Dunwoody. “That’s tricky. People are so unpredictable. However, I would say your safest course of action would be to balance the equation.”

  “What do you mean?” asked Olive, envisioning two numbers hopping onto a teeter-totter.

  “If you know something about this other person that he or she wishes to keep secret, then he or she is less likely to tell your secret, and risk you telling his.”

  “Isn’t that like blackmail?” asked Olive, pulling out her chair at the table.

  “I would say it’s more like Newton’s third law,” said Mr. Dunwoody, carefully straightening his placemat so that it was parallel to the edge of the table. “Every action has an equal and opposite reaction.”

  “I already straightened the placemats, dear,” said Mrs. Dunwoody, approaching the table with the lasagna pan.

  “Yes, darling. But you know how I feel about parallel lines . . .”

  Mrs. Dunwoody smiled. “That their perfection gives them their identity.”

  “And that’s also just how I feel about you,” said Mr. Dunwoody, kissing the back of his wife’s hand.

  Olive sighed and laid her head down on her dinner plate.

  5

  OLIVE COULD HARDLY sleep that night. Little halfdreams of whirling stacks of books and messages written backward on mirrors kept knocking around inside her brain. Sometimes the messages said things like, The spellbook is in the bloobquepoo, or some other nonsense that was no help at all. Other times, the message said, My house used to be owned by witches! and as Olive watched, the message reflected from one mirror to another and another and another, unfurling into a huge web of repeated words. The web was tangling around her. She was stuck in it, pinned in place and unable to escape. Only the book could help her. It would keep her safe. It would save Morton. She had to find it, before anyone else did. She thrashed and kicked, her heart revving up to panic mode—The BOOK, went her heartbeat, echoing inside of her own head. The BOOK. The BOOK. The BOOK. The BOOK.

  Something let out a loud hiss.

  Olive jerked awake and found that she had been kicking wildly at the sheets. Horatio, who liked to sleep at the foot of the bed, was glaring up at her from the floor.

  “I’m sorry, Horatio,” Olive whispered. “I was having a nightmare.”

  “I see,” huffed the cat. “Well, don’t worry about me. Although it is harder to land on your feet when you’re asleep.”

  “Sorry,” Olive whispered again.

  Horatio hopped back onto the mattress, giving Olive’s feet a wide berth.

  “I did something stupid today,” said Olive, picking up Hershel, her worn brown bear, and squeezing him tightly against her collarbone.

  “Imagine that,” the cat murmured.

  “And now I can’t sleep, because I just keep thinking and thinking about it.”

  “Sounds very productive,” said the cat, settling back into the blankets.

  “There’s this boy living with Mrs. Dewey,” Olive went on as Horatio let out an exasperated sigh, “and he’s the one who asked me about the spellbook. But he only asked me about the spellbook because . . .” Olive’s voice dwindled to a mumble. “. . . Because I told him about the McMartins.”

  Horatio turned sharply. “What, exactly, did you tell him?”

  “I just told him that witches used to live here. I didn’t even say their names.” Olive rubbed Hershel’s head with her chin, which was usually very comforting. Tonight, it wasn’t. “I don’t know why I said anything at all.”

  For a moment, Horatio gazed at the window. Moonlight reflected in his eyes, making them glow like delicate fires. “This boy is living with Mrs. Dewey, you say?”

  “Yes. His name is Rutherford Dewey.”

  “Then I wouldn’t worry too much about it,” said Horatio, nuzzling into the covers.

  “But I am worried!” said Olive. “I keep thinking and thinking about it.” She nudged Horatio gently with her foot. “Horatio, I’m not going to get back to sleep. Could we go visit Morton? Just for a little while? Please?”

  Horatio sidled away from Olive’s nudging toes.

  “Please?”

  The cat gave Olive a hard look. “If I take you, will you promise to let me spend the rest of the night without getting booted out of bed?”

  “Yes. I’ll even sleep sideways.”

  “Fine.” Horatio leaped lightly to the floorboards and trotted through the door. Olive hurried after him, but she turned back for just a moment to tuck Hershel under the covers.

  Squares of moonlight through distant windows gave the upstairs hall its only light. Horatio moved soundlessly over the thick carpet. Olive tiptoed behind him, listening to the house creak and shift, taking up as little space as she could in the darkness.

  They stopped in front of the painting of Linden Street. “Hold on,” Horatio commanded. Olive grasped his tail. The moment her fingers were buried in the cat’s fur, Olive saw the painting come to life. Soft breezes rippled the misty grass. Far in the distance, lights from the houses twinkled and flickered. Horatio hopped over the frame’s bottom edge, dragging Olive’s arm after him. With the familiar sensation of sliding through warm Jell-O, Olive pushed her head through the frame, and then her shoulders, and then her whol
e body was toppling forward, over the bottom of the frame, into the painting.

  She landed in the dewy grass on the other side. The frame floated in the air above her. Horatio, who naturally landed on his feet, was already heading up the soft green hill toward the street, where a few lamps glowed like welcoming beacons. Olive got up and hurried after him.

  It was always evening in Morton’s world. A faint, misty twilight swaddled the painted version of Linden Street, never turning darker or brighter. On this street, no one ever had to go to bed, or come inside for dinner, or get their pajamas on. In fact, since most of the people in this painting had been lured straight out of their beds and into Aldous McMartin’s canvas, they were already wearing their pajamas anyway.

  The first time Olive had visited this painting, the street was eerily still, and faces had peered at her distrustfully through the tiny windows of locked doors. Now the faces peered at her and smiled. Through many of the closed curtains came the soft glow of candles or lamplight. A few people even sat on their porches in the silvery mist, rocking gently on porch swings. One old man in a nightcap raised his hand in a wave. Olive waved back.

  Horatio trotted ahead of her, up the pavement, past the empty spot where the big stone house would have been if Aldous McMartin had painted it, toward the tall grayish house just beyond.

  “I’m going to get you!” someone shouted.

  Olive jumped. Horatio bristled.

  The sound of laughter trailed around the corner of the tall gray house. Instinctively, Olive crouched down in the dewy grass, trying not to be seen. A moment later, a small boy in a long white nightshirt raced around the house’s side, panting and chuckling, reaching out as if he were trying to catch something that dangled in the air just in front of his face. His nearly white hair stood up in tufts, and his face looked like a smiling moon.

  Giving the empty air a wild swipe, the boy tripped on the hem of his nightshirt and sprawled on the grass, laughing. “All right,” he declared, getting back to his feet. The grass where he’d landed got back up too. “You win this time.”