Witness the most important event in the lives of Jaime Madrox and Siren - the birth of their baby! What will happen to X-Factor - and what will be the meaning for mutantkind! All we can guarantee are that the answers are not what you expect - but that's what makes it X-Factor! Don't miss what is sure to be one of the most talked-about books of 2009! Collects X-Factor #39-45.