The Others
The first on the watch stood at the edge of the mountain. Though it was on duty, its gaze was not turned to the south, but towards the pikes of solid, smooth, ice that made up the mountain beneath it.
The second on the watch approached the first. Neither of them have names, none of their kind do. At least, not in the way that we understand names. "What draws your eyes from your post?" The second asked the first.
"I seek to see what the Night King saw," replied the first. Instantly, the second understood. Though they have prepared their march on the South for ages, few of them have ever seen a human, let alone the wall. The second gazed into the ice as well. Though they saw their own images blur, they could see nothing definite. No visions of the enemy's lands or people. Only the Night King can see such things in the ice.
"Where has the Night King gone?" asked the first.
"South," said the second. "To a southern town. He called it Hardhome." They continued to stare into the ice, as though they were children transfixed by their nan's bedtime story. The first and second had always kept their watch. Never before had they left what the southerners call the Lands of Always Winter. But they know the stories, each one of them did.
In the days of old, the eternal cold was not left to the pathetic little spit of land they now stood upon. The cold that prevailed against even the longest and warmest of summers reached far past the human's wall. Man's green, luscious forests were once bare and stark white. Man's blue rivers and lakes were dark grey, and man's deserts in the farthest reaches of the south had dunes of snow instead of sand.
The first and second scowled as they remembered their old dominion. But they remembered it not as two soldiers remembering a failed invasion, but as two people remembering a home lost to an invasion.
It was man who stole the south 8,000 years ago. They wouldn't have prevailed had it not been for their God, the cursed one, the melter, the scorcher, the blinder, the merciless…R'hollor. The first and second shuttered as they thought of the cursed one's name.
The cursed one gave man the strength to defeat the Others, and struck the eternal cold so hard that they could sire no more children.
It took 8,000 years to regain their power, to replenish their numbers, to amass their army of undead wraiths, but at last they have the strength to take what is rightfully theirs.
The first and second, content with the thought of their brethren marching South looked away from the ice—leaving such vision-seeking for the Night King—and resumed their watch, looking towards the South.