When Oʻahu resident Diane Ako set out to find her family’s missing matriarch — a full Hawaiian woman named Helen Maliu who vanished in 1900 and was never spoken of again — she uncovered a journey that led from Honolulu to the shores of Kalaupapa, Molokaʻi. Pili Hou follows Diane and her family as they piece together why Helen left, where she made a second home, and what it means, more than a century later, to pili hou — to rejoin — with the great-grandmother they never knew they’d lost.