Seamus was a carpenter who lived together with his son Milo at Fort Bailey in the 19th century. He appeared in Ginger Snaps Back: The Beginning.
On the day after a hellhound attack on the fort he was repairing the damaged gate together with his son. When the men discovered that one of the dead werewolves was a turned former trapper from the fort, Seamus advocated for abandoning the place altogether but was turned down by Rowlands and James.
One evening when he was sharpening his axe inside his workshop, Seamus was alerted by a noise coming from the attic and while checking on it was startled by a half-transformed Geoffrey Rowlands hiding there causing Seamus to fall off the ladder. Seamus was subsequently killed by the boy. When the other men found his body they also found a strand of hair that Geoffrey previously pulled from Ginger Fitzgerald's face, which caused them to suspect the girl of having killed Seamus.
Seamus knew how to speak the language of the local Native Americans.