The Royal London A and E on Whitechapel Road runs hot from dinner until dawn. The overnight cleaner shift starts at 20:00 and ends at 06:30, with a thirty-minute paid break.

Adaeze Nwosu is forty-two. She was born in Onitsha, Nigeria, and has worked at the Royal London for eleven years, the last seven on overnights.

She is employed by a contractor, not directly by the NHS Trust. She earns 13.85 pounds an hour plus a 22 percent night enhancement.

"It is enough," she says. "It is not enough for London. But it is enough if you are careful."

Her trolley is yellow and red, color-coded for the work. Red mop for the toilets, yellow for the clinical areas, blue for the offices, green for the kitchens. She does not mix them. She has watched new cleaners be sent home for mixing them.

She wears a navy uniform with a red trim, black non-slip shoes from Shoes For Crews, nitrile gloves, and a plastic apron when she enters a clinical area. The apron goes in the orange bag when she leaves the bay.

At 22:14 a resus bay is freed. The patient, a man in his sixties who came in with a stab wound to the abdomen, has gone up to theatre. The nurses pull the curtain.

“The patient, a man in his sixties who came in with a stab wound to the abdomen, has gone up to theatre.”

Adaeze does not enter until the porter has taken the linen and the clinical waste. Then she enters with her trolley.

The floor has blood on it. Not a lot. Enough. She sprays a chlorine solution, 1,000 parts per million, lets it sit ninety seconds, and mops it up with disposable pads. Then a detergent wipe across every surface the patient or the team may have touched. The monitor, the trolley rails, the IV pole, the light switch, the curtain track handle.

It takes her seventeen minutes. The bay is open again at 22:34.

"They need the bay," she says. "There is always someone coming."

She has three children. The eldest is at the University of Hertfordshire studying nursing. The middle one is doing A-levels. The youngest is twelve and likes football. Her husband drives a bus on the 25 route.

They overlap for an hour in the morning before she sleeps. He brings her tea.

At 02:50 there is a vomit spillage in the waiting room. A young woman, drunk, has missed the bin. Adaeze comes with a spillage kit, a sealed plastic packet of absorbent granules, gloves, a scoop, and a yellow bag.

The woman apologizes, crying. Adaeze tells her it is alright. She has children. She is not bothered.

"People are sick," she says. "That is why they are here. I am not here to judge."

At 04:00 she takes her break. She eats jollof rice from a Tupperware in the staff room. A nurse she knows from Lagos sits with her for ten minutes. They speak Igbo and laugh quietly.

She does the corridor outside minors with the dry mop, then the wet mop, then the dry again. The floor shines under the strip lights.

She clocks out at 06:32. The day cleaners are already in. She walks to the bus stop on Whitechapel Road in the rising light.

"The hospital is never finished," she says. "You finish your shift. The hospital, no."