When it comes to NBC's emotional family drama This Is Us , every piece of news is a clue, a scrap of information that we can use to patch together the future of this labyrinthine soap. Entertainment Weekly reported today that actress Amanda Warren is set to play — drumroll please — William's mother, Dorothy. Warren, a seasoned television veteran, is known best for her role as the town mayor on The Leftovers. (She's also had notable roles in shows such as Netflix's Jessica Jones and The Closer.) According to the exclusive report, Dorothy will appear solely in flashbacks alongside a young William. So, that's the news: William's mother will appear on the show. But the real scoop here is that now we know This Is Us will expand even farther into the past. So far into the past, in fact, that the triplets at the center of the series won't even have been born yet. As of now, the show explores two timelines. There's the inception and upbringing of the "Big Three" (the triplets) and there's the current comings and goings of the three as adults. Given that the show was recently renewed for two more seasons, it's not surprising the story lines are set to expand. Now we only have one question: Will they expand into the future, too? I want to see Randall's kids all grown up and driving hovercars. Warren's episode, which will also feature Atlanta's Brian Tyree Henry, does not yet have an air date.