The dead were almost upon them, and there was no escape. After Bran had been marked, they always knew where to find him. Benjen Stark managed to help them escape for some time, but his horse eventually tired of carrying three people. The former First Ranger had decided to stay back to buy time, but he only slowed the dead for a few minutes before he was overwhelmed. Neither the wights nor the White Walkers required any rest, compared to the horse, which needed warmth, food, and sleep. It was no wonder the poor animal expired in less than two days. And while Meera had persisted onwards, dragging Bran on an improvised sledge, she wasn't as strong as Hodor or Summer, nor was her endurance infinite. It didn't take much time for the half-rotten corpses and the icy abominations to finally catch up to them.