Two patients await life-saving surgery at St Mary’s in Paddington and 67-year old Simon needs an operation to remove a cancerous tumour from his oesophagus.

With nearly all of St Mary's beds occupied, the hospital must discharge patients before any new ones can be admitted.

After collapsing at work, crane driver Phil is becoming increasingly paralysed each day. One of the country's leading brain surgeons diagnoses him with a fast-growing brain tumour and decides to perform a potentially life-threatening operation to remove it.

A 98-year-old man, arrives at Hammersmith Hospital for a landmark heart operation. Without the operation, he has only a 50 percent chance of surviving the next six months.

Surgeons are forced to use unconventional methods to get their operations completed against the odds.

In the immediate aftermath of the terror attack on Westminster Bridge, three miles away a major incident is declared at St Mary’s Hospital - the nearest of London’s four Major Trauma Centres.