MI-5, also known as Spooks in the UK is a BBC production; it's about the British version of the CIA. BBC America also cuts a lot out, a good 25 minutes from each episode in order for it to fit to American broadcast times. Unfortunately, while they don't cut out the basic premise, a lot of the background scenes end up on the cutting room floor. In order to get the information, which also build throughout the series, you need to see the uncut episodes, hence the need for the dvds.
MI-5 is very good, very, very good show. A lot happens in it, tons of action and suspense with very little gunfire, which is nice. There are some scenes that are horriffic as they do show some very explicit torture scenes, which on the dvd go on a lot longer than what was aired.
Volume one stars Matthew MacFadyen-- he breaks my heart watching him try and live a normal life while living a lie in order to maintain his cover and keep those around him safe.
Very good storylines that arc over episodes-- while they may resolve some things, the ramifications still continue to echo throughout the season.
A good solid, well-acted show that will keep you guessing and wanting more.