Nina had a small dog named Biscuit. Biscuit was brown and very energetic. One morning, Nina needed to go to the post office. She had a big box to send to her friend. She decided to take Biscuit with her. She put his lead on and they walked down the street together. The post office was not far from Nina's home. When they arrived, Nina opened the door and walked inside. There were many people in the post office. Everyone was standing in a long queue. Nina held Biscuit's lead tightly. She thought he would be calm and quiet. Biscuit looked around the room with big, curious eyes. He wagged his tail and sniffed the air. Nina smiled and joined the back of the queue. Suddenly, Biscuit saw a cat. The cat was sitting in a bag near an old woman.

Biscuit barked loudly and pulled the lead very hard. Nina was not ready. She dropped the big box on the floor. The box made a very loud noise. Everyone in the queue turned around and looked. The cat jumped out of the bag and ran across the room. Biscuit ran after the cat as fast as he could. He pulled Nina with him. Nina tried to stop, but her feet slipped on the floor. She knocked into a tall stand of envelopes. The envelopes fell everywhere. Papers flew through the air. People moved quickly to get out of the way. A small child laughed and clapped her hands. The woman at the counter stood up to see what was happening. It was very noisy and very chaotic. A kind man helped Nina catch Biscuit.

He grabbed the lead and held it firmly. Nina picked up the box from the floor. Her face was very red. "I am so sorry," she said in a loud voice. "My dog is usually very good." The woman behind the counter smiled at her. "It is fine," she said. "We needed some excitement today." The other people in the queue laughed. Nina laughed too, but she still felt embarrassed. She put Biscuit under her arm and held him close. She walked to the counter and sent her box. She said sorry to everyone again before she left. Biscuit wagged his tail happily at the door. Nina looked at him and shook her head. "No more post offices for you," she said. She walked home quickly and did not look back.

Nina had always considered her dog Biscuit to be reasonably well-behaved, so when she needed to send an important parcel one Tuesday morning, she saw no reason not to bring him along. She clipped his lead onto his collar, tucked the parcel under her arm, and headed confidently towards the post office at the end of her street. The building was busier than she had expected, with a long queue of people snaking all the way back to the entrance. Nina joined the line and glanced down at Biscuit, who was sitting beside her with an expression of polite, if somewhat restless, interest. His ears twitched at every sound and his nose worked continuously, pulling in the unfamiliar smells of cardboard, ink, and strangers. Nina patted his head and told herself that everything would be absolutely fine.

It was not fine. Without any warning, Biscuit launched himself forward with such sudden force that the lead was torn from Nina's hand entirely. A gray cat, which had been sitting quietly inside an open bag belonging to an elderly woman near the front of the queue, had made the catastrophic mistake of flicking its tail. Biscuit's bark shook the room, sending the cat leaping onto the counter in a panic, scattering pens, forms, and a plastic stand of envelopes in all directions. Nina sprinted after her dog, colliding with a display rack and sending leaflets raining across the tiled floor. Staff members ducked behind the counter, customers pressed themselves against the walls, and one small boy burst into delighted laughter as the cat vaulted over a printer and disappeared behind a filing cabinet.

It took a full two minutes, the assistance of a remarkably calm postal worker, and the temptation of a biscuit from somebody's bag to finally bring the chaos to an end. Nina stood in the middle of the post office, breathless and crimson-faced, with Biscuit sitting at her feet as though nothing whatsoever had happened. "I genuinely cannot apologize enough," she said, looking around at the dishevelled queue with a mortified expression. The elderly woman, whose cat had retreated back into the bag and was glaring out with obvious contempt, gave a tight smile and said, "These things happen, dear." The postal worker behind the counter straightened her uniform and processed Nina's parcel without further comment, though Nina noticed she was suppressing a smile. Nina thanked everyone, clipped the lead back onto Biscuit's collar with a noticeably firmer grip, and walked out into the fresh air with her head held just slightly lower than when she had walked in.