A new student and member of Dawson's friend group. She hides a secret about neglecting her grandmother's laxatives, attempts to seduce Dawson, and ultimately joins him to defeat the killer after witnessing her friends' bizarre deaths.
They share group-based companionship amid the murders.
Martina and Barbara are introduced as members of the same friend group at school.
Martina moves from threatened victim to active opponent.
Martina is chased by the killer and later joins the effort that defeats him.
Their connection is primarily defined by shared group membership and danger.
Martina and Boner are both members of the student friend group that discusses the murders and receives letters.