Investigative journalist Tanya Talaga tries to piece together a mystery that dates back 150 years: who were the maternal matriarchs in her family, and how did they become so lost?

Tanya dives into records left behind by her Uncle, looking for answers as to what happened to her family's matriarchs. Her friend Sol Mamakwa joins her to look into his past at Residential School.

Tanya makes an unexpected discovery: two of her great uncles died at Shingwauk Indian Residential School. She joins an Indigenous delegation to Rome, looking for an elusive apology from Pope Francis.

Tanya's journey concludes with a shocking revelation of where Annie Carpenter's final resting place is and the realization that her story could represent those of many other families.