The breakout star of Adrian Lyne’s “erotic” thriller is a six-year-old girl who packs in more charisma than its leads put together. Grace Jenkins has just two IMDb credits to her name–Deep Water and a short called The New Nanny–but it’s safe to say she absolutely stole the show in a movie which also stars Ben Affleck and Ana de Armas. No mean feat. Jenkins is adorable and she’s very funny. But we can’t help but think there is another hidden reading to Trixie’s part in the story, should you choose to examine it. Ostensibly, Deep Water, based on the novel by Patricia Highsmith published in 1957, follows a dysfunctional married couple with a kid (Trixie) who drive each other crazy. Melinda (de Armas) flaunts lovers in front of her husband Vic (Affleck), who is sometimes infuriated, and at other times turned on by his wife’s reckless behavior. He eventually turns to offing her lovers and by the end, it would seem Melinda has become complicit in his murderous antics. It’s perhaps become “their thing.” After the film’s deceptively boring pre-title opening, the first scene we see is of Vic and Melinda getting ready to go out while Trixie dances around to “Old MacDonald Had a Farm.” She’s loving it and won’t turn it off, despite her mother’s obvious irritation. “Trixie, you’re going to drive your mom crazy,” says Vic. “I know!” replies Trixie, joyfully. This is a film that deliberately teases directions for the film to go in, which it then pivots away from (or indeed “red herrings” if you will). “Chekhov’s Snails” (the snails that Vic says are poisonous to eat if not starved) do not go on to poison someone, for example. And Trixie does not specifically drive her mother crazy. But we do wonder. It’s an interesting introduction for a character who plays a small but very significant role in the unfolding drama. We learn early on That Trixie is “brilliant,” as per her dad. At age six she is allowed to choose whether she wants to go to public or private school (she chooses public school), and Vic says sending her to college is the worst thing they could do for her. When her mother says she’ll soon be building bombs like her father, she corrects her by saying he “didn’t make a bomb, he made a computer chip.” It’s established early on, then, that Trixie is loyal to her father, takes after him, and is very smart.  As Vic increasingly treats Melinda like a child, he treats Trixie like an adult. He tells one of Melinda’s lovers, Joel, who’s visiting for dinner that while Melinda wanted to cook but Trixie has banned her from the stove for two weeks. At the same dinner, he has his daughter bring a drink out to her mother’s lover. When Trixie asks who he is, Vic tells her he’s  “a friend of your mother, like Martin McRae,” – the lover Vic has claimed (while possibly lying) to have murdered. Vic is sent up to Trixie’s room to read her stories while her mother and Joel spend time together. Trixie says she doesn’t like Joel and wonders why her mother is different around her lovers. Trixie might be six, but she gets it. In one of the most sinister (and also funny) sequences, Trixie, in the bath, confronts her father about whether he murdered Charlie in the swimming pool. She wants to know how he did it. He denies it. Trixie’s babysitter is teaching her how to play poker (“that’ll come in handy,” says Vic). Later her father gives Trixie a glass of wine for a toast which she energetically clinks–her father is celebrating having just murdered another of Melinda’s lovers, Tony.  The family has a picnic near the gorge where Tony’s body is submerged. Trixie and her dog play a little close to the edge of the water (where the body is somewhat visible). When the next day Vic returns to get Melinda’s scarf and re-weight the body, Melinda finds Tony’s passport and packs a suitcase. But Trixie finds the luggage, throws it in the pool, and shouts, “We’re not going!” It seems to be Trixie who keeps her dysfunctional parents together. Does she know about her mum? Probably. Does she know about her dad? Probably. Is she bothered? The final sequence of the film where she sings and jigs along to “You Make Me Feel Like Dancing” indicates the answer is a resounding “NOPE.”