Maisie Lockwood is a young girl who lives in Lockwood Manor, owned by her grandfather Benjamin Lockwood, an old business partner of John Hammond.
Maisie is Lockwood's granddaughter (In actuality, she is a genetically modified clone of Lockwoods deceased daughter), and lives in his mansion under the supervision of maid Iris and Lockwood's ambitious right-hand man Eli Mills. A fan of dinosaurs, whose skeletons and imagery are very present in the mansion, she at times pretends to be one ambushing Iris.
One day, Maisie finds Mills talking to Gunnar Eversol about how the dinosaurs from Isla Nublar will be taken there, and warns his grandfather about how his plans of taking the creatures to a sanctuary won't be respected.
As Maisie enters the secret underground laboratory and sees footage of Owen Grady taming Blue and the other Velociraptors, she hears Mills talking to Henry Wu and attempts to hide. Once she approaches the Indoraptor cell, the hybrid tries to grab Maisie with his arm, scaring the girl and making Mills discover her. Mills proceeds to lock Maisie within her own room, while requesting Iris to not let her go.
By knocking the key out of the keyhole and pulling it under the door with a rug, Maisie managed to break out of her room, and after going to a balcony, climbed the outside of the house to Lockwood's room. To her sadness, her grandfather was dead. After hiding in a nearby laundry chute to avoid Mills, Maisie got all the way down to the lab, where she found Claire Dearing and Owen, who she recognizes as the man in the raptor video.
After walking through the underground, they get to Eversol's auction from behind some grates, where they see the Indoraptor being brought in. In response to Claire asking about the beast, Maisie replies that they made it.
She is with Owen and Claire when an InGen Contractor is pointing his gun at them and Mills tries to talk them into delivering the girl. It only ends as the contractor is attacked and killed by the Indoraptor. They proceed to run from the Indoraptor in the great hall where Maisie used to play, with Maisie eventually hiding in her bed, as the hybrid's arms reached out to her and its jaws came closer. Owen comes to her rescue.
Both escape to the roof of the mansion, with the Indoraptor approaching them on all fours.
- Maisie is depicted with her hair down, unlike her appearance in the movie where it was in a ponytail.
- Her head recycles Lex Murphy's.
- Maisie is the first human clone to appear in the Jurassic Park franchise.