I loved the book but this was a bit slow, especially at the beginning, so stay with it. I think the use of flashbacks made it more difficult to follow, yet in the book it is done in chronological order.
It should get better next week when more happens. They had to cut down on the gore though, but the Battle of the Somme next week may change that.
I thought the lead actor played Wraysford very well, he is supposed to come across as very cold and unfeeling in the book.