heard the computer whir and beep. She glanced at the

  wafer-thin screen and did a double take.

  “Unbelievable,” Nancy murmured, watching the

  intricate spirals of blue, green, yellow, and purple twist

  around the perimeter of Dennis's screen.

  She grabbed George's arm, bending close to whisper

  in her ear. “Those are the same graphics I saw on the

  threat that was sent to Mr. Lorenzo's computer!”

  7. Elusive Clues and Slippery Suspects

  “What should we do?” George whispered back.

  “I'm going to talk to him,” Nancy said.

  She was next to Dennis in three long strides. “Hi,

  guys,” she said, keeping her voice as casual as she

  could. “Those are really cool graphics, Dennis. Did you

  program them yourself?”

  Dennis's eyes jumped from Nancy to George, who

  was in line at the food counter a few yards away. His

  mouth curved up in a cocky smile as he asked, “Did

  your teammates send you here to spy on the compe-

  tition?”

  He hadn't answered her question, Nancy noticed. “I

  like your colorful spirals, that's all. Did you program

  them yourself?” she asked again.

  One of the red-haired twins answered. Nancy wasn't

  sure whether it was Jake or Philip. “The guy's a

  magician on the computer,” he said, shrugging his

  parka onto his chair back as he nodded at Dennis.

  That made Dennis the most likely person to have

  sent the threat to Mr. Lorenzo, but not the sabotage.

  Nancy knew she couldn't go back to Mr. Lorenzo

  without more concrete proof.

  “One of George's bindings broke loose while we

  were skiing for the second clue,” she said. She watched

  Dennis closely while she told him about the broken tip

  of the screw that had popped loose. “The funny thing

  is, the screwdriver and file were both missing from Mr.

  Lorenzo's tools,” she finished.

  “I'm sure Randy Cohen documented the whole

  dramatic event for his article,” Dennis said. The sar-

  casm in his voice made Nancy bristle.

  “You still think C.J. would sabotage the Challenge

  for publicity?” She waved a hand toward the platform

  where C.J., Ned, and Grant sat. “He sprained his own

  ankle!”

  Dennis didn't bother to respond. “Where's C.J.'s

  shadow?” he asked as his eyes focused on the Omega

  table. “Maybe Randy figured out C.J. is all hot air.”

  Nancy ignored the jabs at C.J. “I noticed you got

  back to Sigma Pi pretty late last night,” she said to

  Dennis. “Over an hour after you left the Eatery.”

  “Will you quit trying to prove I'm the bad guy?”

  Dennis said. “If I'm the one who's behind all this so-

  called sabotage, then why was our team the last to find

  the second clue? I mean, wouldn't the idea be to make

  sure our team gets ahead?”

  He had a point, Nancy thought. Still, there was

  something about the way he avoided her questions that

  bothered her.

  Nancy's eyes fell on Dennis's computer bag. It lay

  unzipped on the floor next to his chair.

  “Well, sorry to bother you,” she said. “See you guys

  later.”

  As she turned away, Nancy made sure her boot

  caught on the strap of Dennis's computer bag. She

  tripped forward, and a jumble of things spilled from

  the bag.

  “Sorry!” she fibbed, crouching down next to the bag.

  “I'll put it back.”

  She kept her eyes open for soap, or a file and

  screwdriver among the notebooks, pens, binoculars,

  gloves, and papers. Before she could touch a thing,

  though, Dennis had leaned over and scooped every-

  thing back into the bag.

  “Now, if you don't mind, we've got a clue to work

  on,” he said.

  Nancy had no choice but to rejoin George at the

  food counter.

  “So?” George asked.

  “He's too slick to answer direct questions about the

  threat and sabotage,” Nancy said. Her focus stayed on

  Dennis as she and George got hot chocolate and

  carried the tray up to their table.

  “Too bad I can't keep this close an eye on Dennis all

  the time,” she murmured. She placed the tray on their

  table, then glanced back over the railing at the Sigmas.

  “From up here we really have a good view of—”

  She broke off suddenly and snapped her fingers.

  “That's it!”

  Ned blew on his steaming cocoa, glancing curiously

  across the table at her. “What's it?” he asked.

  “I get the clue—part of it, anyway. I think I know

  why baseball is for the birds,” she said. “It's because we

  need to get a bird's-eye view before we can solve the

  clue. That's why a high fly scores!”

  George nodded, taking a fresh look at the clue. “And

  a ground ball doesn't make it because you don't get the

  right perspective on the ground,” she said.

  “It makes sense,” C.J. said. He pointed at the

  bottom of the paper. “Check out these parts about your

  ears ringing, and a high fly towering over to score.”

  “The bell tower!” they all said at once.

  Nancy leaped to her feet, grabbing her parka and

  team hat. “Let's go!”

  “Watch that step,” Grant said as they made their way

  up the bell tower stairs fifteen minutes later. “It could

  still be slippery.”

  Nancy saw C.J.'s frown as he carefully planted his

  cane above the step that had been soaped. “I wish I

  knew who did that. . . .” he mumbled.

  “We're working on it,” Nancy assured him. “The

  important thing is that the sabotage isn't working. We

  still have a good chance of winning.”

  “Brrrr!” George shivered as they went into the cir-

  cular room at the top of the bell tower. Wind whipped

  through openings in the stone wall, stirring the bells

  that hung from the stone ceiling.

  “Wow. You can see the whole campus from here.”

  George said as she stared through one of the openings.

  “Not to mention the town,” said Grant. After taking

  a pair of binoculars from his backpack, he looked out

  the other side of the tower. “Hmm. Isn't that Randy?”

  Nancy borrowed the binoculars and spotted Randy,

  with his bright yellow parka and white-blond hair, just

  opening the door to SportsMania.

  “It's him, all right.” Nancy frowned, watching as

  Randy disappeared inside the store. “It's funny that he

  suddenly stopped sticking so close to you, C.J.,” she

  commented. “I wonder what he's doing?”

  “Um, guys? We're supposed to be finding the next

  clue, remember?” George said dryly. “Shouldn't we

  look for Needlenose on First, Flying Colors on Second,

  and North Point on Third?”

  Shaking herself, Nancy joined Ned, George, and

  Grant on the other side of the tower.

  “Look!” George pointed to a tall antenna at the top

  of the science center. “Do you think that c
ould be the

  needlenose?”

  “It looks more like a needle than anything else I

  see,” Nancy said. “And if that's first base . . .”

  She looked farther out over the campus, trying to

  spot something that could be flying colors. “The flag!”

  she crowed, pointing to the top of the Student Center.

  “It's in about the right place for second base.”

  Ned and Grant immediately turned to look for third

  base. “The North Chapel!” Ned cried, pointing to an

  ornate spire that rose up from a stone building near the

  dorms.

  “So home base would have to be opposite the flag,

  and closer to us than the chapel spire or the antenna.”

  “The administration building?” George suggested.

  The four-story brick building was down a small slope

  from the bell tower. Nancy lifted the binoculars to get

  a close-up view.

  That was when she spotted Joy, in her red jacket,

  halfway up the side of the building. Her body was bent

  in a V, with her feet pressed flat against the bricks and

  her hands holding on to a drainpipe that rose vertically

  from the ground to the eaves of the building. Sunlight

  glinted off a plastic snowflake that hung from a window

  ledge just above her head.

  “The next clue is there!” she said. “But so are the

  Deltas.”

  The Omega team got rock-climbing shoes, har-

  nesses, and ropes from the Clues Challenge head-

  quarters at the Sports Complex. By the time they got to

  the administration building, the Deltas were gone.

  “Joy used the drainpipe to hoist herself up,” Nancy

  said, letting her backpack drop to the snowy ground.

  “She wasn't wearing a harness or anything, but. . .” She

  stared up at the sheer brick facade of the building,

  broken only by windows. The snowflake, hanging from

  a third-story window, seemed impossibly high. Huge

  icicles hung from the eaves. Some of them almost as

  tall as she was. “It looks pretty dangerous.”

  “I can do it,” Grant said. “I've done lots of rock

  climbing. As long as I have good traction, it'll be a

  piece of cake.”

  Nancy was glad to see that the gloves Grant pulled

  on had a rubberized palm. His climbing boots were

  flexible, with textured rubber soles that stretched

  around to cover the sides of his feet and toes. Taking a

  deep breath, Grant stepped onto the wall with one

  foot. It held firm against the bricks as he hoisted

  himself up on the drainpipe with his hands, angling his

  body out in a V.

  “Good luck,” George said.

  Nancy watched silently, not wanting to do anything

  to break his concentration. She hardly dared breathe.

  “Keep it up,” C.J. murmured as Grant climbed

  slowly and steadily past the second-story windows.

  “You can . . .”

  All of a sudden he frowned. “Did you guys see

  something move up on the roof?”

  Nancy shaded her eyes with her hand. “Yes!” She

  gasped as something flashed above the eaves. It looked

  like an arm, but the sun made it hard to see clearly.

  Crack!

  “What—”

  Nancy didn't have time to finish her question. A

  huge icicle broke free from the eave and plummeted

  right toward Grant's head.

  8. Look Out!

  Moving instinctively, Nancy grabbed her backpack and

  hurled it at the brick wall as high and as far as she

  could. Her eyes were locked on the deadly point of the

  icicle that was falling toward Grant's head.

  With a thump the backpack slammed into the icicle,

  then ricocheted off the bricks and fell to the ground.

  “Hey!” Grant flinched as chunks of ice rained down

  on him. His hands slipped on the drainpipe. For one

  awful moment his body swerved unsteadily. Nancy

  feared he would lose his grip altogether, but somehow

  he managed to get a steady grip with his hands and

  feet.

  “Wh-what happened?” he asked, his face white.

  George, Ned, and C.J. stood frozen in shock as

  Nancy vaulted toward the main entrance of the ad-

  ministration building.

  “Someone knocked that icicle off the roof,” she

  called over her shoulder. “I'm going to find out who!”

  “Wait up! I'm coming,” Ned called.

  They raced up the central staircase to the fourth

  floor. Nancy paused breathlessly at the top of the stairs.

  There was a seating area with plants and windows that

  overlooked the quad. The place was deserted.

  Not surprising, Nancy thought. People wouldn't be

  working in the administration building on the weekend.

  Hallways led left and right, but she didn't see any way

  to the roof.

  “This way!” Ned said, and led them past half a dozen

  doorways to a stairwell at the end of the hall.

  “Footprints.” Nancy pointed to wet boot prints on

  the stairs above them.

  She pushed through a metal door to the roof and

  looked around. No one was in sight, but a trail of prints

  led through the deep snow to a raised parapet along

  the roof's edge and then back to the door.

  Nancy hustled through the snow to the parapet and

  peered over the edge. Directly below her, she saw

  Grant had made his way down the wall to the ground.

  At least he was safe.

  “Hey, Nancy!” Ned called from behind her. “Look

  what I found.”

  She turned to see him bent over the snow a few feet

  from the door. Ned straightened up, holding out a

  slender tool in his gloved hand.

  “A file,” Nancy breathed.

  “And this,” Ned added, holding up a green glove in

  his other hand. “Whoever was up here must have

  dropped them.”

  “Which means that whoever knocked the icicle off is

  the same person who filed the tip off the screw from

  George's binding.” Nancy walked back over to him,

  took the file and glove, and put them in the pocket of

  her parka. “Come on. Maybe we can still find the

  person.”

  Ned and she made their way back down the stairs to

  the fourth floor. “Too bad the footprints have dried

  out,” she said. “We'll have to guess which way the

  person went.”

  “There are three stairways,” Ned said. “This one, the

  main stairs we used to get up to the fourth floor, and

  another stairway at the end of the other hall. I'll go this

  way.”

  “I'll take the main stairs. Meet you at the bottom!”

  Nancy pulled open the door to the fourth-floor

  hallway. For a moment she stood there, watching and

  listening. Goose bumps popped out on her arms and

  legs. She was struck by the uneasy feeling that

  someone was there.

  “Hello?” she said, but all she heard in reply was the

  sound of her own breathing.

  Shaking herself once, Nancy moved quickly down

  the hall. She tried each door she passed. Bursars Of-

  fice, Student Records, Fi
nancial Aid . . . They were all

  locked.

  She was just about to start down the center stairs

  when a voice coming from the other hallway made her

  stop.

  “I could have gotten in big trouble last night.”

  Nancy jerked her head around. I know that voice!

  she thought.

  Hardly daring to breathe, she tiptoed down the hall

  toward the sound. Just beyond a rest room door was a

  bank of old-fashioned phone booths set into the wall.

  Three of the four booths were empty. But a half-open

  backpack and red parka spilled through the doorway of

  the fourth booth. As Nancy drew closer, she recognized

  Joy's blond hair. Joy's face was turned away from

  Nancy, but the tone of her voice was clearly annoyed.

  “Okay, okay,” Joy said into the receiver. “We'll meet

  again. But this time don't let me down.”

  In a single efficient motion, Joy slammed the re-

  ceiver into its cradle and swung her arm around to

  scoop up her things. She was halfway out of the phone

  booth when she saw Nancy.

  “Oh.” She paused uncertainly. “I didn't know anyone

  was—”

  Joy stopped talking and stared at the green glove

  that stuck out of Nancy's jacket pocket.

  “Hey! Isn't that—”

  She shoved her hands into her own jacket pockets,

  then blinked in confusion when she pulled out only one

  glove.

  “What are you doing with my other glove?” she

  demanded. Nancy was surprised by her accusing tone.

  Joy acted as if she was suspicious of Nancy, instead of

  the other way around.

  “I found it on the roof,” Nancy said. “Right after

  someone knocked an icicle from the eaves that nearly

  skewered Grant.”

  Joy blinked. “You don't think I. . . No way,” she said,

  shaking her head firmly. “I haven't even been on the

  roof.”

  “Well, someone was. And you're the only one

  around.” Nancy glanced up and down the deserted

  hallway. “What are you doing here all by yourself?

  Shouldn't you be with your team?”

  Joy yanked the zipper of her backpack closed. “I

  don't have to put up with your third degree,” she said,

  tugging on her parka and slipping her backpack over

  her shoulder. “And I won't stand for your making

  trouble for me.”

  “My team is the one being affected by the sabotage,”

  Nancy pointed out. “C.J. hurt his ankle slipping on the