Many traditional "noir" stories and characters were explored in earlier episodes, including the ditzy but attractive secretary, the cagey but well-informed partner, and clashes with crooked lawyers, femme fatales and meddlesome, too-good-for-their-own-good cops. These were usually given a modern or supernatural twist. The style and focus of the show changed considerably over its run, and starting late in season two the original noir idea was mostly discarded in favor of more large-scale supernatural-themed conflicts. In later seasons, the mythology and stories became increasingly complex; in Season Four, one of the characters on the show itself described the storyline as "a turgid supernatural soap opera." Whereas the show initially dealt with the difficulty of being kind to people on a personal basis, the show ultimately focused on Angel's status as an archetypal Champion for humanity, and explored ideas such as moral ambiguity, the spiritual cost of violence, and the nature of free will. The enduring theme throughout the series was the struggle for redemption. "Angel" explored trust motifs as an increasingly central focus of the show. In the first two seasons, there were sprinklings of deceit and treachery, but in the last three seasons duplicity began to pervade the thematic structure, culminating in Season Five when almost every episode included some kind of double-cross, trickery, or illusion. An idea presented in Season Three was that even prophecy can betray, as they are often deceiving if not plain lies. In Season Five, it is repeatedly emphasized that the characters can trust no one in their new situation. The series is also notable for harsh betrayals within the cast of main characters; such events often having lethal consequences. "Angel" depicted the feelings of loneliness, danger, and callousness often attributed to the urban Los Angeles megalopolis. The divisions between the ordered world of the day and the chaotic world of the night have been trademark themes of "noir" and by depicting a protagonist who literally has no daytime life, the series was able to explore these same themes in more dramatic, metaphorical ways. As the series progressed, the creators were able to explore darker aspects of the characters, particularly Angel, who commits a number of morally questionable actions, and periodically reverts to his evil persona Angelus. The series was released to DVD, produced by 20th Century Fox, from 2001 to 2005. In 2009, the DVDs were repackaged into slimmer cases, which resemble regular DVD packaging.