Marha was a Zensunni girl who, like Selim, came from Naib Dhartha's tribe on Arrakis. Marha claimed she was skilled with the knife, killing and injuring two opponents when one tried to rape her in the spaceport; this event marked her with a crescent scar above her eyebrow. Tired from Dhartha's commercial policy about the marketing of melange to off-worlders, she left the tribe in order to seek the legendary Selim Wormrider. Marha made Ishmael swear to shelter and advise her son.