At breakfast, Mom announced that there would a meeting on Saturday. A pet meeting. That’s when we would let her know if we had saved enough money. That’s when we would discover what sort of house we would be living in — would we have a lousy, catnip-infested, stuck-up, stinking cat house, or a friendly, outgoing, best-friend-boasting dog one?

“Are you guys getting close to earning enough money?” Mom asked. “The month is almost over.”

“Very close!” I said, my mouth full of oatmeal.

“Exceptionally close!” said Lexi, nearly coughing up a cornflake.

“Really, exceptionally, brilliantly close!” I shouted in a garbled croak. Some oatmeal dribbled down my lip.

Lexi didn’t even try to top me.

But this time I meant it. I had counted my money when I woke up. I’d make it to five hundred dollars with a day to spare, unless something went horribly wrong.

And what could possibly go horribly wrong? I thought. After all, karma was on my side.

“We’ll see on Saturday,” said Mom.

I tried to read Lexi’s face. Was she confident? Nervous? Scared? I couldn’t tell. Lexi’s expression didn’t change. She might have smirked, I wasn’t sure. If she did smirk, it was a very, very small one.

“Otto!” yelled Mom. “Your shoes don’t belong in the kitchen!”

I walked Barker again. It was part of a subscription, which means I had already been paid for walking him. It sort of felt like walking a dog for free. But a subscription is a commitment. It’s a responsibility. And I was nothing if not responsible.

Besides, I really liked walking Barker. Every time he looked up at me, his tongue wagging and his eyes filled with joy, I wanted to melt right into the pavement. I would have walked him for free.

But walking him for money was even better.

I pretended Barker was my dog, ambling along the sidewalk. My dog, barking at strangers. My dog, sniffing invisible creatures and standing at attention when threatened by a flower.

My dog would be the sort of dog that wouldn’t run away, even if I dropped the leash, because it loved me so much.

My dog wouldn’t shed. It would growl at crooks and sisters.

My dog would be smart and do tricks.

Most of all, my dog would love me more than anything in the entire world.

I couldn’t imagine anything better. It would have made this month — the grades, the soccer, the guilt — all worth it.

“Hey, wanna play soccer?” It was Eric and Kyle from the soccer team, approaching and waving from down the block. They kicked a soccer ball back and forth between them. “We’re heading to the park,” said Eric.

“I shouldn’t,” I said, glancing at Barker.

“Oh, come on,” said Eric. “We’ll play for ten minutes. Twenty minutes tops.”

“Well, I …”

“We’ll meet you there.” They ran ahead.

It was tempting. It was. I could tie Barker to a branch while I played. This time I’d tie the leash exceptionally well. Barker wouldn’t mind. I needed the practice. I imagined Coach Drago applauding as I kicked in the perfect goal. “That’s the way!” he’d scream. “Otto’s back!”

“It was nothing,” I’d answer, blushing. “I’ve just finally had some time to practice.”

Playing soccer wouldn’t be goofing off. It would be the responsible thing to do. I wasn’t just practicing for myself; I was practicing for the team. I couldn’t let them down!

I didn’t pay attention to where we were walking. I was too busy kicking an imaginary soccer ball through the net and dreaming of Coach Drago’s excited clapping. That’s why I didn’t notice the broken bottle on the sidewalk. I should have been more alert. I should have been looking out for Barker, who was distracted by a biker and didn’t see it, either. His shrill bark snapped me out of my daydream.

Immediately I knew something was wrong. Barker stood on three legs, whimpering. Blood dripped from the pad of his lifted paw. Shattered glass covered the sidewalk. Who would leave a broken bottle like that?

Barker looked at me with those large eyes of his, but they weren’t smiling eyes. They were helpless, desperate ones. There’s nothing you can do when a dog looks at you like that, other than wish you were the one bleeding from stepping on glass. I would have traded places with him in a nanosecond.

I knelt down to look at Barker’s paw. There was a glass shard sticking out, and I started breathing hard. My heart pounded. A couple of weeks ago I would have panicked.

Dogs can feel your nervousness. I had to be calm, but not for me. Barker would be calm if I was calm. I took a deep breath. I slowed my heart.

“It’s okay, boy.” I held his paw in one hand and rubbed his neck with the other. “We’ll get help.” I slowly pulled the piece of glass out. Barker whined.

I knew of a small vet clinic at the edge of downtown. Just a few blocks away. I couldn’t expect Barker to walk, though, and he was too big to carry all that way. “Stay here, boy!” I said to Barker. I dropped his leash, which felt strange, but he wasn’t going anywhere. Not with that foot.

“Help!” I yelled, flailing my arms to catch the attention of a small and sporty green convertible driving past. The car screeched to a stop. The door opened. The driver stepped out.

“Thank you, mister,” I said before I even noticed who it was. The man wore an apron with blood splattered on it. He was tall and frowning. It was Mr. Schnood.

“Oh. It’s you,” he grumbled.

I ignored his groan. “The dog. He’s been hurt. Please, Mr. Schnood. Can you drive us to the vet? It’s only a few blocks away.” He paused. He looked at me, and then at Barker. And then at his car.

I expected him to drive away. He didn’t look very happy to see me. But then he nodded. “Okay. Let’s go.”

As it turned out, Mr. Schnood wasn’t so bad. He helped me carry Barker to the car and put him on the passenger seat. I climbed into the very tiny back. I could only fit on the seat by sitting sideways.

“We should call your mother,” Mr. Schnood said, taking out his cell phone.

“No. She’s out of town,” I blurted out. I didn’t want Mom to hear about this. Or Lexi. She would just say I was being irresponsible and that’s why the dog got hurt.

No, I needed to prove I wasn’t mostly responsible. But that I was really responsible.

“Who can I call?”

“No one. I’m fine. Really. Just hurry.”

When we pulled up to the animal clinic, Mr. Schnood helped me carry Barker into the building. There were four or five chairs in the waiting room, but they were people chairs, which was kind of crummy for the animals. They were the ones who were sick. There was a bulletin board with pictures of dogs that owners must have sent in (I doubt the dogs dropped them off). I recognized a couple from my Dog Party Debacle. The place smelled like cleanser. For some reason I thought it would smell like animals.

“Thanks, Mr. Schnood. You can go now. We’ll be okay.”

Mr. Schnood sat down. “I’ll wait. You might need a ride back home.” He grabbed a dog magazine from the end table and opened it.

As I said, Mr. Schnood turned out to be pretty decent when you weren’t knocking over his cans or putting grocery bags in the wrong car.

A man in a white lab coat was eating a fast-food hamburger behind the counter. He had a scraggly white beard that reminded me of a sheepdog. I didn’t know who he was until he put down his burger and walked around the counter and held out his hand. It had mustard on it. “Sorry. I’m eating a late lunch. I’m Dr. Radis. What happened?” He wiped his mustard fingers on his sleeve. Still, I didn’t bother to shake it.

“His name is Barker. He stepped on some glass,” I said. “Is he going to be okay?”

“We’ll take good care of him,” the doctor assured me. He looked more closely at the paw. “It doesn’t look so bad. More of a puncture. Let’s clean it up.” Dr. Radis lifted Barker and carried him. “Your dad should come, too,” he said, nodding to Mr. Schnood.

“Oh. Um, he’s okay right there,” I blurted, avoiding the whole that’s-not-my-dad-and-this-isn’t-my-dog conversation. I didn’t know whether the doctor would treat Barker if he knew he wasn’t my pet. “He faints at the sight of blood. And he doesn’t speak English.”

“Then why is he reading a magazine in English?”

“He likes to pretend.”

The doctor sighed but nodded. We went through some doors and into an examination room. It was sort of like a human doctor’s room, although the exam table was small, steel, and on the floor. Dr. Radis put Barker on the table, and it lifted when he pressed a button. After washing his hands, the doctor listened to Barker’s heart and pushed on his belly and chest.

“It’s his foot,” I pointed out.

“Just checking,” said the doctor.

Finally, he treated the paw. “It’s okay, Barker,” I said, petting his side. I fought my nerves so that I stayed calm and my heart didn’t race. “You’ll be fine, boy.” Barker gave my hand a lick and then closed his eyes as the doctor cleaned out the cut and wrapped it in a few layers of bandages. The final bandage was bright green, which was way cooler than a plain old white bandage if you ask me.

When the doctor finished, Barker panted and looked up at me with those deep ice-blue eyes. You’d have melted if you saw them, believe me.

If this is what being really responsible felt like, then I guess I liked being really responsible.

“He will heal right up in two or three days,” said Dr. Radis. “The bandages should be changed every morning. I’ll give you a couple days’ worth of pain medication.”

“I don’t think I need pain medication,” I said.

“It’s for the dog.”

That made sense.

We went back to the reception area. “How much do I owe you?” I asked, fishing out the wad of bills I kept in my pocket.

“It was eighty dollars. But he took care of it,” said the nurse, gesturing to Mr. Schnood.

Mr. Schnood looked up from his magazine. “Is he okay?” I nodded. “Ready to go?” I nodded again.

Barker wore a little bootie on his paw, so he could walk, but slowly. It obviously hurt, but he didn’t complain. That was the sort of stand-up dog Barker was.

“I want to pay you back,” I said to Mr. Schnood as we approached his car. This was my responsibility.

“It’s on me. I’m sorry I had to fire you. We’ll call us even now.” He learned over to me and whispered, “Mrs. Printz is a pain in the rear, if you ask me.”

I got into the backseat, but I couldn’t let him pay. I was the one who was responsible. Me.

I removed eighty dollars from my pocket. “Here,” I said, thrusting it forward as Mr. Schnood backed out of the parking lot.

He shooed me away with his hand. “It’s on me.”

“I insist,” I said again, putting the money on the front seat. “My mom will pay me back.” Which of course was a lie, but Mr. Schnood shrugged and took the cash. “Thanks for driving,” I added.

“No, thank you. That magazine I was reading gave me an idea for a new display. A pyramid of dog food bags.” He paused. “Bags, not cans,” he added warily. After driving in silence for a bit he said, “I guess you can come back to the store. Not to work,” he quickly added. “But to shop. You’re not so bad, kid.”

“You’re not so bad, either, I guess,” I added awkwardly.

Mrs. Mundsen didn’t take the news of her dog’s injury as badly as I thought she might. I explained what happened and gave her the instructions for taking care of Barker. I didn’t think she was going to hire me again, but she didn’t yell or threaten to sue me.

That night at home, I lay in bed with my shoe box next to me. I counted my money, twice. There was no way I could earn enough money for a dog now. I had even missed all the rest of my appointments that day because of the vet visit. I called my customers to explain. They were understanding, except for Mrs. Linkletter, who complained that she never should have bought a subscription. I told her I would throw in an extra dog walking day and that made her happier.

But I knew I’d already lost the challenge, and there was nothing I could do to make enough money to win, short of selling all my clothes and Mom’s computer. And selling Mom’s computer wouldn’t get me a dog, it would just get me grounded for the rest of my natural born life, my unnatural life, and probably three or four other lives as well.

Yet I felt calm, just like they say you’re supposed to feel when you walk dogs. Even though I was going to lose the challenge. Even though I would be living with a cat, I had taken responsibility. Being responsible means accepting what happens even when things don’t go right. Being responsible means not blaming someone else, either. Even though I really, really wanted to blame everything on Lexi.