I read the book last week. I bought it 18 months ago as a holiday read and was told that it was definitely not a book to take on holiday!
I loved it! I hope the programme is as good. I am sure the scenes will be toned down for TV.
In the intro of the book Sebastian Faulks says he got the idea whilst working as a journalist and he had to accompany WW1 veterans back to the trenches in 1988. One held his hand and said he his best friend had been blown up and he didn't want to leave him there so he put him in a sack, but no piece was bigger than a leg of mutton. Later they found his friend's grave and he was so pleased that he was remembered.