Normally when things are this good you predict 'it's all downhill from here' but with this series things never dip really - small bumps in the road perhaps but the quality is uniformly high.
These are close on four hour dramas. They weren't shown in one stretch on the telly but if you get the boxed set that's how they'll be presented - with no pauses in between and no signs of where they would have gone either. (Thank you British television.)
Episode I is written by the creator of the series and it's nigh on perfect with all the stacked decks where you want them and a masterful revelation of the lead character 'gradually'. Tom Wilkinson great in a small supporting role.
This one has everything and some of the sequels won't have it as well. Upon viewing the start of episode two the girlfriend immediately blurted 'one was cacophony in the station room - this one is a light hum'. You want that cacophony and this one has it.
Get comfortable for you're in for a heady four hour ride.