Kingdom Hospital came out with a 4-disk set consisting of all 13 episodes. This DVD is misleading in that it implys it is about what happened after the series (or that more is given to the plot). This is actually just some episodes that are on the 4-disk set. It's a mystery to me why they released this DVD as well, but it's a waste of your queue allotment. All there is to the Kingdom Hospital story is on the 4-disk set - you can skip "The Beginning" and "Post Mortem" as these are the same thing. An added note... the 4-disk set includes special features on disk 1 and disk 2.
I made the mistake of renting Kingdom Hospital: Post Mortem. If you are interested in watching Kingdom Hospital rent the one that has four discs. These discs have all the episodes and Post Mortem only has the last 5. I like the show and the series, but Post Mortem and The Beginning are a waste of time.