Nick Clegg's meteoric rise to become Deputy Prime Minister has brought into sharp focus the role of the number two. It's not always an enviable position. So why, in British politics, does the deputy so rarely reach the summit? And why, when he does, does it usually end in disaster? Think of Michael Foot or Anthony Eden. These programmes talk to a number of the politicians who became deputy leader of their party or even Deputy Prime Minister but who just didn't reach the summit -- people like Roy Hattersley, Michael Heseltine, Shirley Williams, Margaret Beckett and Geoffrey Howe. Some never really wanted the job in the first place, others found it an exciting experience from which they learned a lot. One likens it to a bucket of warm spit, only worse. So is there a jinx on the role of the deputy? The political commentator, Julia Langdon, finds out in The Curse of the Number Two.