Late October 2016… Two patients await life-saving surgery at St Mary's in Paddington, the biggest of the five hospitals in the Trust. They will both need a bed on the intensive care ward. But the hospital is full to capacity - on red alert - and there is only one bed left.

Sixty seven year-old Simon needs an operation to remove a cancerous tumour from his oesophagus. As he is being prepped for surgery, St Mary's takes a call from an ambulance speeding to London en route from Norwich. In the back is 78 year-old Janice. She is being ‘blue lighted' to St Mary's with a ruptured aneurysm in her aorta and is less than six hours from death. If she arrives alive, and survives the surgery, she - like Simon - will also need a bed in intensive care.

The surgeons - Professor George Hanna and Richard Gibbs who are slated to carry out the operations are at the centre of this film. We follow their attempts to do the right thing for both patients in a complex life-and-death situation where two into one just won't go.

"To cure Simon, he needs to have the operation", says Professor Hanna. But, in a world where beds are at a premium, operating can seem like the easy part. As surgeon Gibbs remarks: "I sometimes feel that I spend as much energy on trying to organise and manage beds… to allow us to just get on with [the operation]".

Simon has had his cancer operation cancelled once already and having completed extensive chemotherapy needs his surgery to be completed soon. Simon explains, "You just rely on them to do the operation. You just want it done; you reach a point when you just can't keep putting it off forever."

Consultant in charge of the Intensive Care Unit, Simon Ashworth, is also feeling the pressure. It's down to him to make the difficult decision about who to admit for surgery: "It does feel to me like the elastic is a bit nearer to breaking now than it perhaps ever was. Everyone thinks what they're doing is important and guess what everybody's right".

Two floors down from ICU, 18-year old Deborah is anxiously awaiting a life-saving bone marrow transplant to cure her of chronic sickle cell disease. St Mary's is the only specialist centre in the UK that has pioneered a treatment for sickle cell disease with bone marrow transplants that aren't the normal 100 per cent donor match. Deborah's brother Sam is a 50 percent match and the family's hopes rest on him being able to provide her with the bone marrow she needs to save her life.

After collapsing at work, crane driver Phil is becoming increasingly paralysed with each passing day. Kevin O'Neill, 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. But as the clock ticks, securing theatre time for Phil is not straightforward in a hospital approaching full capacity.

O'Neill and his colleagues deal with some of the country's most complex and challenging neurological cases. Their work is so in demand, the department has one of the longest waiting lists in the country.

But the hospital is determined to clear the backlog of patients, some have been waiting for their operations for over a year. The pressure is on for O'Neill and his team to get through a packed list.

At the same time the Trust is pioneering a form of non-invasive brain surgery that replaces knives and drills with MRI focussed ultrasound waves. Consultant neurologist Dr Peter Bain says: "The first time I saw an operation like this was on Star Trek". One of his first patients is Selwyn, a 52-year-old painter and decorator with an uncontrollable tremor. If successful, Selwyn's operation could pave the way for significant reductions in brain surgery recovery times and, potentially reduce patient waiting times for some brain surgeries .