A boy named Noah leaves school with his friend Harry after taking a test. As they stay glued to their phones while on the school bus, Harry asks Noah if he’d like to hang out for the easter celebration, but Noah says he can’t, because his family is headed to their beach house for the holiday.
When Noah gets home, his mom, Jo, calls his dad, David, to ask where he is, since he’s running late.
David apologizes for the delay and says they’ll leave in the morning, because he still has something to do at work. Jo is disappointed to hear this because she has packed all their luggage, but she says it’s fine.
She then goes to prepare the table where the kids will eat dinner. While they’re at the table, Noah is mean to his sister, Emma, when she asks for his help, and he makes her angry.
Later that night, David arrives home and goes to see Noah, who is still playing games in his room. Despite his attempts to say sorry to Noah for coming late and making them postpone their trip, Noah doesn’t respond to him, and David asks him what’s wrong.
Noah complains about school and life in general, saying he thinks he sucks at everything he tries to do. However, David encourages him to think differently, and this helps him feel a lot better.
The next morning, David gets another call asking him to come to work, and because of this, he tells Jo to leave with the kids, and he’ll meet them there.
With that, Jo takes the kids to the beach house, and not long after they arrive, the kids head to the beach to play. Noah tries to surf in the water, but he realizes it’s too cold, so he backs off.
As he steps back, Emma sees a box inside the sea, and tells Noah about it. He agrees to go and check what it is, but as he enters the water, the box seems to be stuck and hard to pull out of the water.
Noah forcefully pulls it out, and it ends up landing on the shore not far from where Emma is. As she’s about to touch it, Noah tells her to leave it for him. Before he tries to touch it, the box opens, and they see a shiny glass crystal that keeps making a weird sound.
As they both look curious about what the crystal might be used for, her mother Jo calls them to come in, and Noah tells Emma to keep it a secret and tell no one.
Emma agrees, and they secretly take the box into their room. Inside there, Noah continues to check the crystal to see what it is. Just then, Jo comes in to call them for dinner. She sees the crystal and asks where they saw it.
Noah explains that they saw it on the beach, and it might be useful. However, as Jo touches it, she sees that it’s really light in weight, and she tells him it’s unlikely to be useful.
Later that night, while Noah is asleep, Emma takes the box from under his bed, and decides to check it. As it opens, Emma sees a stuffed bunny toy and some other items, including some shells and a slimy material. Noah wakes up right in time to see this, and he’s not happy.
He’s also surprised to see the new stuff, and as he tries to drag it away from her, one of the items from the box falls and breaks into several pieces.
They immediately start packing it together, and not long after, Emma starts mysteriously communicating with the bunny. Suddenly, she spins a piece of the broken item, and it starts floating in the air.
Noah is shocked to see this, but as he tries his own, it doesn’t work. It then appears that only Emma can spin it, and she does it for all the pieces, until shiny spiral lines form over it.
She puts one of her hands in it, and it seems to break down into several particles. Noah immediately drags her hand out, but nothing seems to happen to it. As they wonder what the objects they found could be used for, Noah says it might be dangerous, and they need to be careful.
Elsewhere, Noah’s teacher, Larry, wakes up from a dream and tells his fiancé, Naomi, that he keeps having the same dreams.
While Naomi seems to think it’s about lottery numbers, Larry says he always sees a shape in his dream sucking him up, and he can’t just explain it.
The next day, after Noah stares so much at the crystal, he’s able to use his eyes to replicate it around him. Just as he looks around, he creates a portal that sucks in a can and takes it to Emma’s table.
Emma looks shocked to see this, but Noah doesn’t know how he was able to do it by just staring at the can. Shortly after, Emma says her bunny, which she calls Mimzy, knows a lot of things. She says it knows their names and everything about them.
Just as she says Mimzy tells her their dad will call the house, a phone rings in the house, and Noah looks shocked.
As they enter the house, Jo asks them to guess who called, and Emma says she knows their dad is coming. Jo is shocked, and she asks how Emma was able to know this. Emma just responds by saying Mimzy told her, but Jo doesn’t take it seriously. Not long after, David arrives, and they welcome him to the beach house.
The next day, David takes Noah to go golfing. Even though he says he’s not interested, David asks Noah to try. He finally agrees and gets into position, with David giving him some advice on how to hit the ball.
However, Noah is able to form crystals in his path, and as he hits the ball, he opens up a portal that takes the ball to reach the farthest mark. David is excited to see this, and he tells Noah that golf might just be his sport.
The next day, while Larry is teaching the class, Noah keeps drawing several objects on paper. After class, he doesn’t take the paper with him, and as Larry starts cleaning up the class, he sees one of Noah’s drawings and immediately runs to find him.
He shows Noah the drawing and asks what inspired him. Noah says he just draws things that come to his mind, and shows Larry even more drawings. Larry begs to borrow the drawings, and Noah says he doesn’t mind.
Later that day, Larry and his fiancé realize that Noah’s drawings are similar to an ancient drawing Larry always sees in his dreams. They both look shocked to see this, and wonder how Noah might be connected.
Days later, Noah participates in his school’s science competition ,and comes up with an amazing project that forces Larry to ask his parents if he had any help. As they play it down, saying he and his sister are just gifted, Larry says it’s more than that because Noah’s project could win the National Science Fair.
That night, Emma sees a girl named Alice holding a bunny resembling Mimzy in a book, her babysitter, Julie, reads to her. Emma starts talking about how she found Mimzy in a box on the beach. She also starts asking about aliens, and the likelihood of other creatures in outer space.
As Julie gives her opinion, saying she doesn’t really believe in all that, Emma says she can do magic.
She tells Julie it’s a secret and she must not tell anyone. Julie plays along, and Emma goes to get the spinners and starts spinning them, until the shiny lines show again. She also puts her hands inside, and as Julie sees it break down into several particles, she loses her cool and thinks Emma is an alien.
She runs out of the house, and even though David tells her to come back for her money, she doesn’t turn back.
David comes in to ask Emma what’s happened, but she tells him she only showed Julie a magic trick. Noah also secretly packs up the spinners, so that David doesn’t see it.
Much later, after the kids are in their rooms, Jo says something suspicious is going on in the house, and even before they think of what happened to Julie, they need to understand how Noah was able to pull off a brilliant science project all by himself.
David says he’s sure it’s nothing serious, and the kids are just smart, but Jo says before they went for the Easter holiday, Noah was always asking for her help, even with the simplest assignments, and the sudden change is shocking. David tells her not to worry much about it as he believes everything is fine.
That night, Noah gets an urge to take the crystal close to the slimy object from the box. As he tries to stop it, the crystal gets sucked in, and it transforms into something different.
It then causes a surge that results in a blackout across the state. Noah immediately hides the object when his parents come in to check on him.
In the morning, Noah shows Emma the object, which he calls a generator, saying he didn’t mean to cause the blackout. He adds that they need to get rid of everything, but Emma disagrees, saying Mimzy told her everything will be fine.
Much later, Noah and Emma have the same dream about a bridge that is formed with crystals.
Elsewhere, the regional director of the FBI named Nathanial, tells his team at an emergency meeting that they need to find out what caused the blackout, because it could be an imminent terrorist attack.
They also pinpoint that the surge came from a residential neighborhood, and this causes them to worry about why such a surge would come from there.
The next day, Larry and Naomi visit Jo to discuss Noah’s drawings. Larry starts by telling Jo that something is going on with Noah, and she agrees that she has been noticing the same thing.
Larry and Naomi then bring out their books, and show Jo that Noah has been randomly drawing ancient symbols used to represent the universe, including one that is a map of the past and future.
They soon tell Jo they think Noah is special, and Naomi can tell by checking some markings on his palm. Noah walks in and asks Naomi to check his palm.
Jo permits her, and after Naomi checks, she doesn’t find what she’s looking for. However, when she checks Emma’s hands, she sees that Emma is the special one. Everything is too much for Jo to process, and as Larry and Naomi are about to leave, they see Mimzy and ask Emma about it.
Emma says Mimzy is her teacher, and she knows about the drawings from Noah’s book, and this shocks Naomi and Larry.
That night, Jo has trouble sleeping, and as David tries to get her to sleep, she says it’s hard for her because Emma knows things she shouldn’t know at her age.
In the morning, David joins the family for breakfast, and there, Jo asks Noah about his glasses, but he says he doesn’t need them anymore, because he can now see well. Jo looks worried, but before they know what’s happening, Emma says Mimzy is sick.
David looks confused, but Emma continues to say it. David finally asks her to put Mimzy away and pass him the sugar. Suddenly, Emma uses her mind to lift the sugar and drop it on David’s plate, leaving him completely shocked.
He immediately calls Larry and Naomi to explain the situation to them. They sound really worried, and Larry suggests taking the kids to see a neurologist, to check on their brains. Jo and David agree, and just as they wonder where the kids are, Noah runs down the stairs to tell them something is wrong with Emma.
As they run to check on her, they see Emma floating in the air, saying Mimzy also taught her. Jo gets really scared and asks for all the things they found on the beach, including Mimzy. She seizes them forcefully and dumps them in the garbage bin.
That night, Noah goes to get everything back and returns Mimzy to Emma, who is happy to get it back. She then starts talking about how she needs to look through the spiral lines formed by the spinners.
She shows Noah the book where Alice is holding Mimzy. He is surprised to see this, and Emma tells him that even though Alice lived over a hundred years ago, it seems she failed to complete her mission with Mimzy, and that’s why the bunny is with them again.
She tells Noah she can complete the mission with his help, but she needs to look through the sparkly lines to properly understand what to do. After she puts her face in, she starts seeing different things, and by the time Noah pulls her out, something seems to be wrong with her.
Noah immediately calls his parents, but as they get there, Emma seems to be fine again, and she says she only had a dream where she saw a strange scientist.
The next day, David and Jo visit the hospital to get the results of the children’s brain tests. There, the doctor lets them know that Emma’s brain is much more advanced than even adults. He also says it’s nothing he and his team have seen before, and they’d like to carry out more tests.
The next day, David arrives home early from work, and tells Jo he took a leave of absence to be there for his family, until everything with the kids gets resolved.
Jo thanks him, and as the kids also come to meet him, they hear someone ring the house bell. Jo goes to open it, and it turns out to be the FBI, led by Nathanial, who tells them the surge that caused a blackout originated from their house, and they need to be sure it’s not a terrorist attack.
As they’re about to be taken away, Emma says she needs to take something, and as she’s led to her room, she returns with Mimzy. Jo looks shocked to see the toy, and Noah says sorry for bringing it back to the house.
The family are taken to a research institute, where the kids are asked about the spinners, and other items from the box they found on the beach.
Emma volunteers to show what the spinners can do, and as she spins them and puts her hands in between the sparkly lines, she says Mimzy taught her. The researchers immediately take Mimzy from her to analyze it. They then figure out that it’s made with tech, that has not even been dreamt of yet.
Shortly after, Nathanial asks them to bring in more experts, but the lead researcher says there are no experts regarding what’s happening.
Emma asks to talk, and then she says Mimzy told her the box came from the future. She also says things are not going well in the future, and that’s why a scientist from there decided to send stuffed animals, to get DNA samples from the present world to help them provide a solution.
Emma says they also need to act fast, because Mimzy is dying, and it needs to be sent back as soon as possible. She adds that Mimzy is the last stuffed animal to be sent, and the mission must not be ignored.
Nathanial doesn’t know what to believe, but he dismisses everyone. That night, Emma and Noah orchestrate an escape with all the items from the box. Noah is able to summon insects to block the cameras, while Emma is able to use her mind to open the doors.
They finally get everything but realize they need more. As Noah wonders where they’ll get it, Emma says there are more spinners under the bed in their beach house. With that, they head out on their own, and Noah drives them away in a truck.
The truck soon runs out of gas, and just as Noah wonders how they’ll get to the beach house, Emma says help will come. Surprisingly, Larry wakes up from a dream, where he drives to the spot where the truck stopped. As he doesn’t understand what it means, he says he’s going back to bed, but Naomi tells him he needs to follow his dreams.
They head out together, and are surprised when they see Noah and Emma waiting for them at the exact spot. Larry is shocked, but Naomi tells him not to ask questions and just take the kids to where they’re going.
With that, they head over to the beach house, and on their way, Emma starts crying, saying she’s scared they won’t make it, and her tears touch Mimzy.
Elsewhere, Nathanial tells David and Jo that he’s working on finding their children. Just then, an operative tells him they’ve found the truck they took. As they mention where it is, David says the kids are headed to the beach house, and they must head over there too.
Larry and Naomi get the kids to the beach house, and after they pick up the spinners under the bed, they head out to start the process of sending Mimzy back to the future.
Emma starts up the spinners and puts Mimzy inside. She also tells Noah to start the generator and use it to create the portal. As he does this, Emma decides to say goodbye to Mimzy, but as she touches it, her hand gets stuck, and the spinners start lifting her along with Mimzy.
David and Jo arrive in an FBI helicopter, and they see what’s going on. As they wonder how they’ll save Emma, Noah asks David to hold on to the generator while he goes to get her. David collects it, and Noah is able to pull down Emma before the portal sucks up the spinners and takes Mimzy to the sky, before it all disappears.
The family gets reunited, and Nathanial also says sorry for keeping them in custody earlier. After that, David invites Larry and Naomi into the beach house. As she enters the house, Emma looks at the sky through her window, and says she’ll miss Mimzy.
Elsewhere, Mimzy arrives at the future scientist’s lab, and with Emma’s teardrop, he’s able to use it to save humanity.