Mittell's book "Complex TV" outlines a historical poetics of contemporary television series, which he calls "complex TV." Mittell argues that the "complex" television series of today feature an array of storytelling techniques which cannot be adequately understood through the use of cinematic and literary theory. This is especially the case with seriality, i.e. the fact that television series are told in several, separate episodes. To Mittell, this form of television drama emerged in the early 1990s and is characterized by its use of “narrative special effect” which is to say that a program sometimes "flexes its storytelling muscles to confound and amaze a viewer”, e.g. by using flashbacks in innovative ways.