Winters for the Sinum herd had never been too difficult until now. Before, they always had an experienced lead horse to guide them through the harsh times. Through starvation, thirst, predator attacks, even the nastiest blizzards when the vision was near limited to inches in front of you. They had always made it until summer was able to hit, until grass started poking from the ground once more and birds flew over their heads. They mourned their casualties during that season sure, as the cold got to the old and sickly and horses were picked off by predators, but they never were as bad as they could have gotten and fared better than the smaller bachelor or mare groups wandering the plains and forests that made their home. Times change however, and their luck has never been so bad.
Their lead stallion, however wise he had been, had finally succumbed to the cold on his seventh winter leading the herd. It had only been the first week of frigid snow. Their deputy fell sick and met the lady known as death. Their lieutenant went missing during a predator attack and hasn't returned to them since, so he's assumed dead. The Sinum herd has nobody to lead them. Their lead stallion never appointed a lead mare, as he hadn't found the heart to accept someone after the old lead mare died giving birth two years ago, the foal not making it either. Seeing the herd desperate and some already accepting that this winter they will all succumb to the elements one way or another, a lone mare appears from the blizzards to offer the Sinum herd her help.
This lone mare claims she can help them survive and knows tactics that can save this herd until the first sign of grass and birds begin to show once more. That she can help them live to see another day until the sun is bright against their backs again. The catch is that they must accept her and her two friends into the herd. Their lead stallion always had a key rule in place that was always absolute and kept them safe, to never let a loner close, mare or stallion, but with the worst of the cold quickly coming to claim their lands and with no high ranked horse to lead them, will the herd turn the complete stranger away or cast aside their deceased lead stallions keystone rule and take her as their temporary lead until the grass is green again?