In case it’s not readily apparent, spoilers are ahead.
I’ve always wondered how new White Walkers are born. It seemed out of sorts to think of them as producing in any fashion human. That was a damn good ending and the first time I’ve seen the Land of Always Winter, the frosty home of the White Walkers. Craster’s policy of providing infant boys to the White Walkers served to protect him from the ravages of those unearthly monsters. But it served another more sinister purpose of swelling their ranks. How many infant boys do you think Craster gave them over the years?