Scientists don't know that much - not in the sense of being absolutely sure. We are the 95% kind of people. We talk in a precise and still strangely vague way about our ideas. We can be "fairly conclusive" or note that "all the current evidence supports ..." but this time is an exception. For once, humbly, I know.
I know I'll never see my father again.
I was analysing his fate even as the phone rang. No one calls at 7am on a Saturday; not unless it's trouble. Before my mother said a word, I was thinking: stroke or heart attack? An incontinent future spent dribbling soup or major surgery and an uphill struggle until the next collapse? The clinical details mattered little to me. My dad was a portly behemoth of a man, fond of Springbank malt and a good rioja. I gave him short odds of surviving either fate.
It turns out I was wrong - well, not wrong exactly. Scientists aren't wrong: we just have to refine our hypotheses occasionally. My father was only admitted to Addenbrooke's hospital, in Cambridge, "for observation" after his suspected flu turned into vomiting, diarrhoea and delirium. The GP who called the ambulance diagnosed an allergy or infection, but by the time I reached his bedside, to say he was unwell would be like saying lung cancer is a bit of a chest complaint. An overnight stay in hospital was never going to fix it.
Until that day, my father had just been part of the landscape; an assumed presence, willing to offer money and advice that an independent daughter could refuse. Our relationship had been light-heartedly competitive. Both biochemists by training, we bickered over whose research was the more significant. Did his paper in Nature beat mine in Neuron? And long after he started his own company and became more of a businessman, science was still a language we shared. There is comfort in believing that, as the biologist and broadcaster Lewis Wolpert once said, "Science has nothing whatsoever to do with real life." But with my father transferred to intensive care, it dawned on me that I hadn't lived our profession to the full; I had simply been working in a lab. Being a scientist is not about what you do, but how you think and see the world.
I saw doctors as fallible. I've supervised enough research projects to observe their mistakes: apparatus assembled incorrectly, calculations 10-fold out, and precious biological samples accidentally thrown down the sink. Acute anxiety drove me to study every aspect of my father's illness. This was no mere infection. It was septic shock with multi-organ failure. In most cases, streptococcal infection only causes a sore throat but unrestrained, in the bloodstream, the bacteria can collapse blood pressure, demolish great chunks of flesh and leave a trail of destruction matched only by the opening sequence of a Bond film. My father's body was no more than a man-sized culture dish, replete with every possible nutrient. The expanding colony was the estate agent of the 1980s or the e-commerce broker of the 1990s. The conditions were right, the raw materials were all there. It had everything it needed to make a killing.
We tried everything we could to save him. His consultant enrolled him in an international clinical trial for an experimental new treatment. My husband prayed. I watched the bleeping boxes around his bed. My father became little more than a well-monitored medical statistic, discussed as temperature (38-40°), blood pressure (90 over 50), milligrams of dopamine and anaesthetic infusion rates. Only when patient 1347065 regained consciousness - six days later - did he become human again.
I raced into the intensive care unit, ignoring the sink and the futile command to wash my hands. I felt my heart would burst. What was I to expect? What if he didn't know me? What if he didn't know himself? What if, what if: and when I saw him, the protruding tubes, the monitors, his public physiology, all faded away. It was like seeing my newborn children for the first time - only better. This was no inanimate grey body. It was my father again and I was his daughter. Those open eyes changed everything and thankfully, all he could remember of his illness was waking up with unbelievably cold feet.
Ventilated, he just stared at the ceiling, awake but not fully conscious. He later explained that he was trying to will the ceiling tiles to change places, to reveal some bigger picture that he was sure existed. When the priest administered the last rites to the liver-transplant patient in the adjacent bed, my father was unmoved. He knew that man would die but he was too ill to see himself as part of the same condition.
Gradually he improved and for weeks I harangued the doctors in a manner I knew was unbecoming and unlikely to change his fate, but I couldn't stop myself. What was his plasma potassium, his vancomycin level? Were the swabs back from the lab yet? The last week was unfettered frustration. We would have emptied our combined bank balance for him to see a tree from the window or have a different filling in his sandwiches.
My father was released, triumphant, into the late June sunshine with a revised view of the future. True, his immune system would be for ever impaired and compensations would have to be made. There would be no more oysters, no drinking water of unknown origins and constant vigilance for early signs of infection was vital. I felt nothing but gratitude. All critical bodily functions had been restored. His brain was as sharp as it always had been and each time I bid him farewell there was something warmer in his kiss, something more intense in the way he sent me on my way.
"Drive carefully, Ruthie," he said, for the first time ever. There was no inkling of irritation or urgency in his manner. Each comment was tempered by a gentleness that lived closer to the surface.
Suspecting that this was just a temporary reprieve hard won by Addenbrooke's best (with some help from Alexander Fleming and a score of anonymous blood donors), I pledged to make whatever time was left the best it could be. When we visited my parents' winter home in Florida, my father and I would set off to swim before the sun, or the rest of the family, was awake. With cicadas humming and fluorescent blue dragonflies darting across the water we swam towards the dawning sunrise, soaking up the pleasure of heat on our faces. On a good day my father did six lengths. When he managed 10, I felt he could survive for ever.
For ever turned out to be about nine months. We collected him from the airport, just after Christmas. He appeared through Customs like a returning rear admiral: tall, handsome and neatly dressed in his navy blazer with its shiny brass buttons, thinning hair combed smoothly to one side. But his illusionary wellbeing evaporated like dry ice as he slipped his hand into the crook of my arm. It was such a telling, little act. We always walked with my arm in his. Now I could barely feel the weight of it, so light was his touch.
The deconstruction of his life was like a reversal of development. Most cell divisions occur in the first three months as life takes form. With cancer, most shrinkage occurs in the last three months when life dissolves. And the transformation from life to death is something never to be forgotten. Despite days, weeks and months of anticipation, I was unprepared for the shock that separated his last breath from the unfulfilled expectation of the next. Knowledge should have protected me but at 6am on January 26, he became something I couldn't - and still can't - understand. No longer a living presence, just cold, dark matter. The well-worn, maroon leather slippers that sat untidily at the foot of his bed and the spectacles he used to take on and off with irritating frequency seemed more part of him than the leftovers on the bed.
I fantasised about what I would give to see him again. My right arm, would be the classic reply, but wouldn't an arm be a lot to give if it only postponed the inevitable? What about a hand, a finger? What weight of flesh for a day?
There can be no bargain. I know I will never see my father again.
His genes are still here, of course. As a gene machine, my father was a great success; his personal packets of DNA endure in abundance. My three brothers and I each have 50% of his genes and our 12 children have another 25% apiece. We are a pretty prolific family; procreation is one of our skills. By my calculations, Dad's genes have multiplied 500%. Richard Dawkins would be proud.
And he will always be a part of me - the very way the brain works guarantees that. As we learn, permanent changes occur; neuronal architecture is modified by experience. As they say in forensic medicine, "every contact leaves a trace." For me, for his friends and family, his legacy is not in the archives of the company he built, nor in the plaque listing him alongside other past captains of the golf club. It is written in our minds.
Thinking like a scientist helps, it really does. But I know that it won't ever stop me from feeling like a daughter. I miss him so.
· Ruth McKernan has written about her father in her book Billy's Halo, which was published this week at £16.99
