“A puppy?” Lizzie asked her aunt when she’d picked up the phone in her mom’s study. “What kind? Are we going to foster it? How old?”

“I’ll explain everything when you get here,” said Aunt Amanda. “Can I send your uncle over to pick you up and bring you to Bowser’s?”

Lizzie thought for a moment. She had really been looking forward to some quiet time at home. Plus, there was the total awesomeness of having Charles call her Beautiful Genius all day. But Aunt Amanda was hard to resist. She ran a doggy daycare center called Bowser’s Backyard (named after her big old golden retriever), and she knew more about dogs than anybody in the world. Lizzie had learned a lot from her.

Lizzie loved to help out at Bowser’s Backyard, but lately she’d been too busy with her dog-walking business to be able spend much time there on weekday afternoons, when Bowser’s was full of dogs. It was unusual for Aunt Amanda to need her help on a weekend, when things were quieter. Lizzie was curious. What was up with this puppy?

“Lizzie?” Aunt Amanda asked. “What do you say?”

“Sure,” said Lizzie. “I’ll be ready when Uncle James gets here.” She hung up and went back to her room to put away her scrapbook stuff. Then she headed downstairs to let her parents know where she was going.

A few minutes later, Lizzie heard a honk outside. She checked out the living-room window and saw the Bowser Mobile, with its POOCHES license plate, pulled up in front. “That’s Uncle James,” she told her parents. “I’ll see you later.”

“Don’t come home with a puppy,” her mom said drowsily. She lay on the couch with newspapers strewn all around her.

“Bye!” said Lizzie. She wasn’t promising anything.

“Later, Lizzie,” said Charles, who was sprawled in the middle of the living-room floor, reading the Sunday comics to Buddy and the Bean.

Lizzie put her hands on her hips and glared at her brother.

“See ya, Beautiful Genius,” Charles said, rolling his eyes.

“Bootifulgeenie,” echoed the Bean. “Mootifulbeenie. Gootifuldeenie,” he chanted, laughing his googly laugh.

“That’s better.” Lizzie, the Beautiful Genius, held her head high as she stepped out to meet Uncle James.

“Hey there,” he said as she climbed into the van. “Glad you could help out. I’ve got a billion chores to do today, and we have no staff on weekends, so your aunt’s stuck by herself.”

“Where’s the puppy?” asked Lizzie. “And what’s the big problem? It’s not like you usually have a ton of dogs on the weekends.”

“We’re picking him up right now,” her uncle said. “And the problem isn’t how many dogs we have. It’s how well they get along.” He turned onto a wide, quiet street lined with big houses set back from the road. “Help me look for number thirty-eight,” he said. “That’s Oscar’s place.”

“Oscar!” Lizzie said. “What a great name for a puppy. What breed is he?”

“That breed stuff is more your aunt’s specialty,” said Uncle James, shrugging. “He’s a little guy, with kind of wiry black-and-gray hair. He has this funny mustache and beard, and bushy eyebrows.”

“Sounds like a schnauzer!” said Lizzie. “Cool!” Dog breeds were her specialty, too. Every night she studied her “Dog Breeds of the World” poster, and she had no trouble telling a Nova Scotia duck tolling retriever from a Chesapeake Bay retriever.

“And there he is right now,” said Uncle James as he pulled over in front of a big brick house with white pillars. A woman stood in the front yard, holding one end of a red leash. On the other end of the leash was the most adorable puppy.

“Oh, look at him!” cried Lizzie. As soon as the van came to a stop, she unbuckled and climbed out. She couldn’t wait to get a closer look. The puppy was like a little cartoon character, with his mustache, long wiry beard, and wild eyebrows. As Lizzie approached, he bounced up and down at the end of his leash on stiff, springy legs, letting out happy little woofs.

“This is Oscar,” said the woman. “And I’m Susannah.”

“Susannah, this is Lizzie,” said Uncle James. “She’s our niece, and she’s terrific with dogs. She’s going to help out with Oscar today.”

“Hi, Susannah. Hi, Oscar,” Lizzie said as she knelt to pet the puppy.

Oscar climbed right up onto her and licked her face, tickling her cheek with his bristly mustache.

Hello! Who might you be? You smell absolutely delectable!

Susannah looked surprised. “Wow, he really likes you! Schnauzers are usually a little shy with strangers.” She handed his leash to Lizzie. “Please tell Amanda how much we appreciate this. We’re really at our wits’ end. We love Oscar, but it’s just not fair to Sarge.”

“Sarge?” Lizzie asked.

Susannah pointed toward the house. Lizzie saw a dog watching them from a picture window. He looked like a German shepherd. “Oscar and Sarge just can’t seem to get along,” she said. “We’ve had Sarge for three years, and he’s the sweetest guy ever. He’s our darling. We adopted Oscar because we thought Sarge would like a friend. But it seems as if we brought home an enemy instead.”

Lizzie looked down at the puppy in her arms. Who wouldn’t get along with this little goofball? Maybe Sarge was just jealous, the way Buddy once was when the Petersons had been fostering a miniature poodle named Sweetie. Buddy couldn’t stand it when anybody paid attention to that puppy. Lizzie nuzzled her cheek against Oscar’s.

“We love Oscar,” said Susannah. He’s smart, he’s funny, and he’s terrific with my two little boys, Thomas and Peter. I thought things were improving between him and Sarge, but then this morning they just kept getting into squabbles.” She held up her hands. “Maybe it’s hopeless.”

Lizzie stood up, holding Oscar. “Well, Sarge can have a nice quiet day, anyway. We’ll take good care of Oscar.”

Susannah reached out to pet the funny little pup. “Bye, baby,” she murmured. “You have fun at Bowser’s.” She held his paw for a long moment, her face very serious. Then she turned away. Lizzie had the funny feeling that Susannah might be fighting back tears.

Lizzie brought Oscar back to the van and climbed inside. “I still don’t get why Aunt Amanda needed my help,” she said to Uncle James. “How much trouble could this puppy be?”

“You’ll see,” said Uncle James as he started up the van.