As there appears to be no danger of spoiling it for anyone, what happened was this... back in the war years a young girl died in a barn fire. Her ghost then appeared to haunt (and in one case cause the death of) the cast of characters who may have been responsible for her death. It was a ghost story combined with a whodunnit as the key plot element (apart from all the scary ghost stuff) was who set the fire that killed the girl, and why?
The series was well filmed, acted, written, and produced - excellent, overall - and as it was spread across three periods (40s, 70s, and contemporary) it was interesting to watch and try and work out who was who in the different generations and how they related back to each other etc etc. It was also fun seeing the 70's era stuff (my era!) as the recreation was done really well.
Anyway, four or fives episodes and we get to the big climax and.... here come the spoilers....
...it turns out the ghost wasn't actually haunting anyone in a mean-spirited way (excuse the pun) but was trying to lead them all to the truth in order that they could find peace. A lot of people had carried a life-time of guilt over the fatal fire as many of them actually thought they were the instigator of the blaze; the plotting was such that only one person knew the truth - the girl that had died.
All of which is okay, having a good ghost isn't a bad thing (they can still be scary) and when the ghost caused the death of a man this helped build the illusion of a malevolent ghost (the death was 'justified' as the man in question had seduced the girl under false pretences,and humilated her).
The problem comes when we finally see what happens on the night in question... and, here's the key that ruins many hours of fine television for me, the girl who dies (th eonly one, who it turns out, knows the truth) is fast asleep and on the other side of many bales of hay when the chap that lights the fire actually does so. So actually she can have no idea who did it.
Now, maybe a ghost of a dead person can/could know stuff that happened out of sight or knowledge of the person whom they're the ghost of? But why take the risk that peoiple will make this leap of faith? Why build an entire drama series around the need for a single character to know what really happened one night and then have her alseep and out of sight when it happens? And if a ghost can know everything then it opens up all sorts of other questions / plot points about why a ghost that was trying to help people stood by and watched them when they made all sorts of other life mistakes caused by their misplaced guilt.
Anyway, it's probbaly just me - witness my last crit-week discussion about plot holes. Maybe I'm just sensitive to such things right now

Back to work...
Derek