The first episode of a new series is always a minefield. How do you introduce the main protagonists, set the scene, hint at what you hope will be the show's long and brilliant future and still cram in enough storyline to keep viewers watching until the end? In this regard, perhaps Nurse Jackie was assisted by its brief 30-minute slot (of which the actual show only filled about 26), since this left no alternative but to focus and trim ruthlessly.