The second series, The Second Guest is similarly set with 25 stories, except this time the main victim is a woman who has just taken a taxi home from her best friend's wedding ceremony. (Source: AniDB)

The third series, The Last Train is set with 26 stories during a bizarre train ride that Gregory embarks upon. (Source: AniDB)

The first series is a set of 25 stories about a male businessman arriving at the hotel after taking a train home from work. He encounters the mysterious owner of the hotel, an old mouse known as Gregory, who suggests that he stay a while. Soon, the man becomes drawn into a bizarre series of events taking place within Gregory House as he tries desperately to escape from this bizarre purgatory. (Source: Wikipedia)

The fourth series, The Bloody Karte (presented as a side series on the DVDs) is a set of 12 stories about Catherine working in a mysterious hospital. (Source: AniDB)