Saturday is a novel set within a single day -- 15 February 2003. Henry Perowne is a contented man - a successful neurosurgeon, happily married to a newspaper lawyer, and enjoying good relations with his children, who are young adults. What troubles him is the state of the world - the impending war against Iraq, and a general darkening and gathering pessimism since the New York and Washington attacks two years before. On this particular Saturday morning, Perowne makes his way to his usual squash game with his anaesthetist, trying to avoid the hundreds of thousand of marchers filling the streets of London, protesting against the war. A minor accident in his car brings him into a confrontation with a small-time thug called Baxter. To Perowne's professional eye, something appears to be profoundly wrong with this young man. Baxter, in his turn, believes the surgeon has humiliated him, and visits the opulent Perowne home that evening, during a family reunion - with savage consequences that will lead Henry Perowne to deploy all his skills to keep this doomed figure alive.