A twenty-four-hour whirlwind of death and life.This is the heart of Simon Limbeau.This is the black box of his twenty-year-old body, circulating five litres of blood each minute, compressing itself a hundred thousand times each day. No bigger than a fist, yet it is capable of pumping blood through sixty thousand miles of blood vessels. This heart has leaped, swelled, melted, sunk, and now, on this glacial winter night, it rests and recharges, readying itself for the day ahead.5.50 a.m. This is his heart. And here is its story.