By-lang is a wolf term, meaning "deeply away". It is typically when a pregnant she-wolf seeks shelter to give birth away from the pack, the clan, her mate, and most importantly, the Obea, in fear that she will birth a malcadh pup in her litter. Obeas become suspicious of the she-wolves who go by-lang. After going by-lang many she-wolves visit The Sark of the Slough to begin the forgetting if they have given birth to a deformed pup.
Before the books
Many she-wolves have gone by-lang over the course of wolf clan history.Lone Wolf, Morag is searching for a den to give birth. She knew she had to get away from the pack, the clan, her mate, and, most importantly, the Obea. There were several shallow pits, but they offered no shelter. She finds a den but is being guarded by a pregnant vixen, a female fox. Morag shoos the fox away and gives birth to three pups. One has a splayed paw, a sign considering him a malcadh, or "cursed".
Meanwhile, the MacDuncan clan Obea, Shibaan, is looking for Morag. Shibaan had learned to become suspicous when a she-wolf went by-lang. She foils Morag's clever tricks, such as crossing the borders and only urinating in ice-free parts of the river. The Obea takes the splayed-paw pup and places him on an icy riverbank.