born to the beta pair of blacktail deer plateau, casmir migrated with his family to the sentinels, which would become donnelaith for their family. following behati's death, casmir decided he couldn't stay at donnelaith, and ran away to join the maplewood, led by his cousin, saena. his devotion to her and her children led them across the entire region; they settled in the tuktu hinterlands and formed silver creek.

he rose quickly through the ranks, following saena — who suffered a brief bout of amnesia — to retrieve her daughters when their father kidnapped them, but was unsuccessful. their failure led to saena's decision not to return to the creek; she wanted to stay close in case her daughters wanted to come with her again.

casmir dedicated himself utterly to silver creek, refusing to return to donnelaith even after his father died, his mate failed to return, and rowan mayfair was thrown out by aria and constantine. the last action cemented his decision not to go back, and donnelaith eventually ended in a vivid firestorm.

he left the teekon for some time with rowan and their children — time will tell if they remember the name of lasher or if they have only ever known casmir to be their father.