“Peanut butter’s full of calories, Jupe,” warned Kelly. “Bananas, too. Very bad for the figure.”

“They’re high in protein and potassium,” Jupe informed her as he listened to his call ring. “Very healthy.”

“High in carbs and fat,” said Kelly. “Very stupid. Try salads.”

Jupe hung up the phone. “No answer. I guess we’ll just have to go over there.” Jupe licked his finger.

“No, Jupe,” Kelly corrected him with a shake of her head. “We’re playing tennis. You’ll have to go solo.” Her nose wrinkled as she screwed the lid back on the peanut butter jar.

Jupe peeled a banana, then opened the telephone directory. “Can’t. Uncle Titus needs the truck, so I need a lift. Besides, this looks like a case for The Three Investigators.”

“That’s you guys, isn’t it?” Elizabeth said. “I’ve heard of you but, really, what can you do? I mean, you’re teenagers.”

“You’d be surprised at the cases we’ve solved,” Bob assured her. They’d been detecting successfully for several years.

“Yeah, and the gorillas we’ve sent to jail!” Pete spun enthusiastically in a karate yoko-keage side snap kick. He and Bob had learned karate, while Jupe had specialized in judo.

“I’ve got Rome’s address.” Jupiter closed the telephone book and tossed his banana peel toward an overflowing wastebasket. He missed.

“Look at it this way,” Jupe told the girls. “If a virus got into a bank’s computer system, people could lose their life savings. Or if it got into a hospital’s computer system, it could kill patients by messing up the orders for medication. We need to stay on top of this. Maybe Rome can tell us if somebody else used his game disk, and we can track the virus back to the guy responsible.”

“But what about us?” Kelly asked forlornly.

“Bob, I was really looking forward to our date,” Elizabeth said with a sweet smile.

“Sorry, girls, but duty calls,” said Jupiter firmly. “Pete and Bob can’t ignore a line like YOU AND YOUR DATA WILL BE ERASED. That blackmail message means big trouble for somebody!

“Besides,” Jupe added airily, “this won’t take long. We’ll be back in plenty of time for your game.”

Pete’s souped-up, baby-blue dodge Aries squealed away from the passenger-loading curb where Jupe and Bob stood. Since the street was already lined with parked cars, Pete was off to search out another place to leave his wheels.

“That is one hot car,” Bob said.

“And one crazed driver!” Jupe laughed. “Come on, let’s hit it.”

Under swaying palms, Jupe and Bob strode up a wide walkway toward a cluster of rambling stucco garden apartments. According to the telephone book, Norton Rome lived here, and according to the small glassed-in directory that stood next to the sidewalk, his place was apartment 5C.

The guys wove through the complex, passing playing children and Sunday barbecuers in tropical garden settings.

“Hey, Jupe, smell those burgers,” Bob teased. “You can’t tempt me. Peanut butter and bananas are very filling.”

“I’ll bet.” Bob chuckled. “Like concrete!”

5C was a corner unit about a hundred yards in from the street. Like the other apartments in the complex, it had its own flower-lined sidewalk, redwood porch, and tall entry door.

“Newspapers!” Bob said. “I don’t like the looks of this.”

Two newspapers lay on Rome’s porch. Jupe picked them up. “Saturday morning and Sunday morning.”

Bob lifted the mailbox lid. “A gas bill and a computer magazine. Saturday’s mail, probably.”

“I’d say Mr. Rome is gone.” Jupe pushed the doorbell.

“Maybe he’s on vacation.”

The guys waited, and Jupe pushed the bell again. He pressed his ear to the door to listen. Bob tried to peer in the front window, but the curtains were closed tight. At last the guys looked at each other and shrugged.

“I saw the manager’s apartment back there,” Jupe said.

“Let’s go.”

They strode off again. The manager lived in Building 3 in a corner apartment identical to Rome’s. Above the doorbell was a sign that said simply manager. Jupe rang the bell, and instantly a dog started barking.

“That dog sounds big,” Jupe said.

“I’d offer to protect you, but he sounds big to me, too!”

Beyond the door they could hear the trudge of feet and the heavy clatter of long-nailed paws.

“Quiet, Monster!” a woman shouted. “Quiet!”

Jupe and Bob stared at each other.

“Monster?” Jupe said.

The barking quieted, and the door opened just enough to show a pink-cheeked woman with gray hair.

“Yes?” she said. At the waist of her jogging suit a dog’s black nose appeared, followed by a large head wedging into the doorway.

Jupe cleared his throat, his eyes on the enormous head. That dog’s got to weigh one-eighty! He thought. “We’re looking for Norton Rome, one of your tenants?”

Suddenly the door burst wide open and Monster leaped forward. Jupe and Bob jumped away, but they weren’t fast enough.

“Ummmpf!” Jupe fell backward into a bed of pansies, his shoulders pinned by two gigantic paws. Monster’s big, wet tongue slurped up Jupe’s chin, over his nose, and up his forehead.

Bob collapsed with laughter.

“Monster, shame on you!” the woman scolded, tugging on his leather collar.

“Off, Monster!” Jupe tried gamely, but his voice was shaky. He tried desperately to shove the dog away. No luck.

Bob grabbed the leather collar and pulled too. He was laughing too hard to speak.

After one final lick, Monster at last stepped nimbly away. Jupiter got to his feet and tried not to look annoyed.

“Bad doggie!” The woman pointed her finger at Monster. “You go right in the house and stay there!”

Monster lowered his head and trudged to the apartment.

“Some watchdog!” the manager told the guys. “He sounds fierce, but he’s really a baby. The only other time I’ve ever seen him knock someone down was when my niece stopped by. She was eating a peanut butter and jelly sandwich, and Monster went wild. He loves peanut butter!”

Bob broke into fresh guffaws.

“You don’t have peanut butter with you, do you?” she asked Jupe.

Jupe’s round face turned bright red. “Not on me,” he said. “Now about Mr. Rome… ”

“Oh, yes.” She returned to the doorway to pat Monster’s head. “You’re the third person today to ask about him. I wonder why. He’s a very quiet man — a little strange, but aren’t we all?” She chuckled and scratched Monster’s ears.

“Who asked about Mr. Rome?” Jupe prompted her.

“I don’t know their names.”

“Could you describe them?” Jupe asked quickly. “Tell us when they came?”

She thought. “Well, one came this morning. He was a bald man, very severe-looking, and he had on a business suit. The other man was here not long ago. He had black hair and wore a dark green Windbreaker and white sneakers.” She looked down at the high-tops on Bob’s feet. “Like yours.”

Jupe pondered this information. Other people were looking for Rome. Could it have anything to do with the virus?

“Did they say why they wanted him?”

“They said they were friends of his. Are you friends of his too?”

“Sort of,” Bob said. “I mean, he gave a talk once to Jupe’s computer club. Do you know where he is?”

“Out of town for a few days. He didn’t say where, but I got the impression he’d be back shortly.”

The guys thanked the woman and left. Behind them Monster gave a farewell woof. Jupe glanced back, watched the door close, and sighed.

“I thought it was your drop-dead good looks.” Bob chortled. “And here it was your delicious peanut butter scent!”

“You want to talk about animal magnetism,” Jupe retorted, “let’s talk about guys who attract girls like flypaper!”

Jupe turned onto the sidewalk that wound through the complex.

“Hey, where are you going?” Bob demanded. “The street is back there.”