First thing in the morning, we get a call for an “injury.” I read on the monitor that it’s a 30-year-old female with an injury to her hand in the basement of a private house in Kensington.

“Heavy bleeder?” Bronson asks.

I scroll down. “Doesn’t say.”

He shrugs, and we take a leisurely drive over to the address given. It’s one of those squat, two-story limestones with bay windows that would go for $2 million in Park Slope, but this isn’t Park Slope. Kensington is quiet, almost suburban; an un-hip neighborhood due to its distance from the only subway line, the F train. The birds are twittering down the endless rows of tree-lined streets, and I’m sure the stay-at-home-mothers all walk a fine line between feeling peaceful and feeling isolated.

We go up the stoop, ring the bell, and are let in by a woman who says it’s her friend downstairs. “She cut her hand,” she says, leading us down basement steps that are twisting, narrow, and dark. “Watch your head,” she says, as we duck a beam along the ceiling. Bronson clears it, but then conks his head against the next one, and mutters an expletive.

We pass the boiler, the oil furnace, and some circa-1920 utility meters. The concrete floor is ancient and cracked. “It’s the catacombs,” I whisper. It amazes me: No matter how nice the renovation, a building’s basement always gives away New York’s Gothic origins. This one has arched brickwork and, unbelievably, oak wine casks and green glass jugs coated with a thick blanket of dust.

The woman leads us to a brightly lit room in the back. She pushes the door open to reveal a small room illuminated by a single bare fluorescent bulb. Ugly high-traffic carpeting has been laid over the concrete floor. There’s a mini refrigerator, a hot-plate, and no windows. A tiny sink sits in one corner. A narrow, iron-frame bed rests against the wall. Hanging from a hook are a set of lavender scrubs and a hospital ID card.

A petite woman is lying on the bed with a blank expression on her face, holding her hand wrapped in a towel soaked with blood. A cell phone lies butterflied on the blanket beside her. There’s a smell of alcohol and a broken bottle on the floor.

I ask the first woman, “What happened?”

She’s blasé. “Some sort of bad news from home. She went into a fit. I heard the noise and came down.”

“And this woman is … ” Bronson says, trying to figure out their relationship.

“My friend,” the woman says again.

I note the name and R.N. designation on the hospital ID card. She’s Filipino.

“Friend, my arse,” I whisper to Bronson. The woman’s afraid to say “tenant” because of the illegal rooming-situation. There’s no ventilation, and no toilet. I note a saucepot and a roll of toilet paper beside the sink. I imagine she showers at the hospital.

This might actually be a step up. Many foreign nurses never leave the hospital, they sleep on a cot, store personal items in a locker, and eat in the cafeteria. They don’t own street clothes because they don’t need them.

I kneel beside the woman to take her blood pressure, and all of a sudden she jackknifes her legs up. I duck out of the way as they’re swinging over her head, gymnast-style. She springs up and starts screaming, spinning around the small room, throwing herself against the small dishrack. Dishes go flying.

Bronson gets on the radio. “EMS, we need an 85” — that means additional units — “and P.D. for a violent patient,” meaning the police.

“Calm down!” I shout to the woman. She picks up dishes and starts hurling them like a discus thrower in the Olympics. They shatter against the brick wall. She’s still bleeding, and blood is flying. “No!” I shout, shielding my face.

Two cops arrive, wrestle this petite whirlwind to the ground, and cuff her. How they do this without injuring her, I don’t know. “I love you guys!” I say to them. “I want to marry you!”

Satisfied the woman is properly restrained, they look around at her living situation. “Whoa,” one cop says, loosening his collar. “I think I just developed claustrophobia.”

The woman, handcuffed on the floor, is crying into the all-weather carpet. I wonder what kind of bad news she got. A sick child? A deceased parent?

I glance at her ID to check which hospital she works at and, to preserve some of her dignity, kneel down and reassure her, “We’ll take you to a different one.”

Ms. Klopsis is an emergency medical technician on an ambulance in Brooklyn. This column details her observations and experiences. Some names and identifying details have been changed to protect the privacy of patients.