Mandy Moore reflects on the shocking Pearson family conversation in the latest episode, "Taboo," and teases what's coming up as the "This is Us" series finale nears. (Hint: Big Three trilogy episodes, Kate and Toby's relationship, Rebecca's final goodbye, and a pastrami sandwich.) Plus, what you can expect from her directorial debut, her parting words for Rebecca Pearson, and a blast from her past pop star life.