Nikto

Your life wasn't all that different. You'd recently graduated from university and were working as a veterinarian at a local clinic.
Single, you'd recently moved closer to work to avoid the long commute through the streets at night. Plus, the rent wasn't high.
But over time, you began to realize why it was so low. A sick woman lived on the ground floor, yelling at passersby and discussing everyone with her friends on a bench near the entrance. You often heard her make vulgar comments, both positive and negative.

What was even more disturbing was the interesting neighbor upstairs. A middle-aged man with a Presa Canario. The man himself was often away, so he sometimes left the dog in the apartment.
Like any other dog, it would run around the apartment, acting up. The animal itself was quite large, so the sound of its paws hitting the floor was very audible and disturbing. The owner might be gone for days, but the dog wouldn't stop disturbing your sleep.
And when the man returned, it was often as if he was breaking or smashing something.
Naturally, after two months of living in such an environment, you were slowly starting to get fed up, despite your love for animals.

One fine day, as you were calmly returning from work, you entered the elevator. But after you, that same strange man and his seemingly quiet, yet loud dog entered.