The Book of General Ignorance round differs, in particular during the Christmas specials. During the course of the "B" Series special, Fry and Davies swapped places for "General Ignorance", with Fry attempting to answer questions ostensibly written by Davies to stump him. During "D"s Christmas Special, all the "GI" questions revolved around saints. "The Book of General Ignorance" contains a list of 230 questions, most of which previously appeared in episodes of "QI". Each question explains the correct answer, and usually attempts to show why people tend to make the wrong assumptions, or believe certain myths. Each book contains two forewords, one by Fry, the
Christmas by medium past year and giving her own reflections and advice. Many long-running British soap operas have Christmas specials, usually involving a dramatic storyline developed over several weeks which culminates at Christmas. Often these stories are tragic, involving a death, divorce, a dramatic revelation or similar event. Most Christmas specials in the UK are specially commissioned separately to a production season, and many are extended from the usual episode length. For example, the 2007 "Doctor Who" Christmas special was 71 minutes as opposed to the standard 45 minutes, was broadcast six months after the third series had finished and four months before