This set has the last half of the episodes from Supernatural season 4, just as previous season UK releases were first marketed split into part 1 and part2 [there's 22 episodes in season 4]. Obviously this is an attempt to extract as much money as possible from those who missed the UK TV showing and are desperate to see how Dean and Sam are getting on. As this whole season is great, and the best yet, perhaps it's money well spent. Certainly though the episodes from Season 4 Part One were scorchers, although the body count seems to be piling up [yes, Supernatural deserves that 15 rating]. Be careful of which reviews you read though, as some contain a few somewhat massive 'spoilers'. Fortunately the last episode of 'Season 4 Part One's DVD set didn't have a particular cliffhanger other than the question of Lilith not unexpectedly remaining unresolved [and she's no Angel, although she is almost as annoying as one].
The previous part-1 DVD set has a "In the Beginning" series creator commentary, and the out-takes [cut scenes, although these often give away key elements of the plot - so watch them last]. Subtitles in this Season 4 Part 2 are English, English SDH [Deaf & Hard of hearing], 'other language' subtitles apparently might vary but ours had dutch subtitles only, and it's spoken English audio only. The extras in this part 2 set seem to be just the deleted scenes. The complete [PAL] fourth season set is now available, but also investigate the NTSC complete season 4 sets from Amazon international resellers that are reputed to contain a few more extras [e.g. the gag reels]. I suppose we can rejoice the series hasn't been cancelled like so many other excellent shows, although the next season Five is reputed to be the finale season [as planned from conception]. Whilst you're waiting for this DVD set to arrive, do check out 'The Dresden Files', 'Angel', 'Blood Ties' and 'Tru Calling' DVD season sets that my daughter  and I rate as at least the equal of 'Supernatural' [i.e. they are superb]. For those new to Supernatural there is a complete seasons 1 to 4 [PAL] DVD set as well, that's generally excellent value. Supernatural: still very spooky and still highly recommended.