The series begins with a new arrival, surgical registrar Caroline Todd (Tamsin Greig). She suffers from constant embarrassment and bad luck, stumbling from one crisis to the next due to a mixture of her own neurosis, impulsiveness, and general misfortune.
Caroline works alongside two other doctors: Guy Secretan (Stephen Mangan), an arrogant, half-Swiss, womanising anaesthetist, and Mac Macartney (Julian Rhind-Tutt), a suave, desirably fashionable surgeon. It is not long before Caroline begins to develop feelings for both of them, though she is unsure as to which of the two she truly loves.