Caroline and Daniel are twins whose mother died when they were babies. They grow up in a conventional family, their aunt and uncle raising them, and they are truly close only to each other. After their father's remarriage, they're sent to separate boarding schools. When the twins become medical students, a serious accident occurs that somehow seems to happen without damage to either of them, but they cut themselves off from the rest of their family because of it; causing first bewilderment and then anger...