When you think of a list of the best actors of all time, Meryl Streep is sure to be on it, quite possibly in the top spot. That doesn’t make her infallible on set. Icons are people too, and they can sometime forget a line in a pivotal moment while shooting a movie with another formidable talent. It’s not surprising to hear no one is perfect, but it’s funny that Doubt co-star Viola Davis, herself an Oscar winner, had a moment during filming when she didn't want to call out the other actress.Doubt is one of those heavy-hitter movies that resulted in strong reviews and later Oscar nominations for Meryl Streep, Viola Davis, Amy Adams and Philip Seymour Hoffman, and the cast was widely praised for their performances, so you know everyone was bringing their A-game to the set of that 2008 release. From writer/director John Patrick Shanley, who adapted from his own Tony-winning play, Streep plays Sister Aloysius Beauvier, the parish school principal, with Davis in the role of Mrs. Miller, mother of the school’s first black student, Donald. Getting to be a fly on the wall when Meryl Streep, who has played other roles landing her Oscar nominations, and Viola Davis are sharing scenes together is bound to be a masterclass in acting. However, when the two looked into each other’s eyes, they both went silent, leading to an awkward pause, making it the opposite of a great improvised movie moment.While chatting about work and life during an episode of Good Hang with Amy Poehler, the award-winning actress who Timothée Chalamet called one of the greats humanized Streep in a way that only someone on the talent level of Viola Davis could. She said:When you have another actor looking in your face and they're waiting for the line — now, I'm big with this is…. I did this with Meryl Streep in Doubt. She had a line, I had a line, or whatever and then: nothing. I'm looking in her face, nothing. She's saying nothing, I'm saying nothing. Obviously, someone dropped the line. And then I realize she's the one who dropped the line. Meryl freaking Streep dropped the line.In actor speak, “dropping the line” means that Streep either forgot or simply failed to deliver her next bit of dialogue, likely caught up in the moment, which is understandable in this case. Doubt is about the suspicion of child abuse at a Catholic school in New York in the early 1960s, and it delves into issues of faith and devotion, social class and sexuality, and a mother’s love for her child. Portraying that subject matter means feelings will rise to the surface, and an actor’s job is all about embracing emotion. But if you get so caught up that you forget what you’re supposed to say next, take the lesson from Viola Davis’s experience on Doubt that you should just tell your scene partner, even if it’s Meryl Streep. Davis said: And so, then we did it three more times, three more times, that scene. And in my brain, I was like, 'Say the fucking line!' But I can't tell Meryl Streep, 'You forgot the line, Meryl. You keep forgetting the line.’ And finally, we did it. And she was like, 'Why does something feel off?' And I said, 'Because you keep forgetting the line. You forgot the line, Meryl.' And then she goes, ‘Well, why didn’t you say something?!’Streep is hardly the first actor to forget his or her lines. In fact, there's a famous story of a stoned Ted Danson doing the same thing. Regardless, it clearly sounds like an awkward moment for her fellow actress.Davis appears in one scene with Meryl Streep in Doubt, lasting for around 10 minutes, but clearly filming it took far longer. The screentime they share is electrifying and gut-wrenching because of what they’re not saying as much as what they are, so it's interesting a dropped line became so important.