On the day of its 500-year anniversary, Britannia Hospital prepares for a royal visit. Outside its gates, protestors gather - they are opposed to the State hospital's treatment of private, fee-paying patients, and are preventing ambulances from delivering the sick.

Professor Millar drives through the protestors and makes his way to the hi-tech Millar Centre. Here he enters a lift with Mick Travis, an investigative journalist masquerading as a window cleaner, who is keen to record Millar's mysterious experiments on a handheld camera. The footage from this camera is beamed to Travis's colleagues, Sammy and Red, who sit in a van outside the hospital grounds.

On his way to the hospital, Vincent Potter, who is overseeing preparations for the royal visit, tells his right-hand man, Biles, to confront the striking kitchen workers. Their strike has been triggered by the gastronomic demands of the hospital's private patients.

As Professor Millar works on one his numerous experiments, including the mysterious Genesis Project, a member of his team, Nurse Persil, signals to Travis, who is outside on a window-cleaning platform. Because of Nurse Persil's undercover work, Travis is able to secretly record footage of Millar murdering a patient named MacCready and subsequently sawing his head off.

Arriving at the hospital, Potter attends a meeting with Chief Superintendent Johns, Lady Ramsden and Sir Anthony Mount, who are all to help with the impending royal visit. Biles interrupts the meeting to inform Potter of the worsening situation in the kitchens. Potter defuses the trouble by promising the Union Leader, Ben Keating, a seat on the royal table.

Nurse Persil allows Travis into the Millar Centre through an open window. In a side-room she kisses and undresses him, before disguising him as a dead body on a stretcher. She then delivers Travis to a room adjacent to that in which Millar is conducting an operation. However, Travis is soon discovered by Millar's operating team and they knock him unconscious.

With only 95 minutes until the royal arrival, more and more protestors arrive outside the hospital. They attack and seize control of the van containing Sammy and Red.

A hospital power cut means that MacCready's head has become unsuitable for one of Millar's experiments. Millar cuts off Travis's head as a replacement. Nurse Persil surreptitiously takes Mick's camera from his pocket and vows to continue his work.

Rather than cancel the royal visit, Potter decides to go out and reason with the protestors. He strikes a deal with the protest leader - the private patients of Britannia Hospital are to be ejected and, in return, the protestors allow a number of ambulances into the hospital. However, unbeknown to the protestors, these ambulances actually contain the Queen Mother and her coterie.

In the Millar Centre, Millar has stitched Travis's head onto a body composed of parts taken from several different people. Once awakened by an electrical charge, this recomposed creature proceeds to attack Millar and his team, leading to the death of a member of Millar's team as well as of the creature itself.

The Queen Mother begins her tour of the hospital; Nurse Persil films her with Travis's camera. The footage is relayed to the van outside, revealing Potter's duplicity to the protestors. Angered, the protesters climb the hospital gates and clash with the police on the other side. Potter ushers the royal party into the Millar Centre, and has the doors locked behind them. The protestors eventually overpower the police and beat on the doors of the Millar Centre, as the dignitaries file into a lecture room in anticipation of Professor Millar's demonstration.

Millar sits on a stage with his Genesis Project - as yet, a glowing pyramid. He quietens the protestors, who have managed to force open the doors, and invites them to witness his demonstration. With everyone in his lecture theatre, Millar claims that, through his Genesis Project, he has perfected mankind. The pyramid unfolds and Genesis is revealed - a brain wired to machinery. Genesis is given a chance to speak and, in a robotic voice, utters the 'What a piece of work is a man' speech from Hamlet, until it continuously repeats the line 'And how like a God'.