The following version of the book was used to create this study guide: Andrews, Mary Kay. The Newcomer. St. Martin's Publishing Group, New York, NY, 2021. Kindle AZW file.

Letty Carnahan arrives at the Murmuring Surf, a motel in Treasure Island, Florida. It has been less than two days since Letty found the body of her sister, Tanya. Letty arrives at the motel in a used car she purchased during her trip from New York City. Her four-year-old niece Maya is in the back seat. Letty is determined to stay at this small motel because Tanya had a magazine article about it in a go-bag she left for Letty. Letty remembers the promise Tanya had elicited, that Letty would leave town with Maya if anything ever happened to Tanya. Tanya also left a bag filled with cash, an expensive piece of jewelry, and the magazine article. The problems begin when Letty naps in the parking lot while waiting for daylight. A police officer, Joe DeCurtis, wakes her with instructions to move her car. Maya needs to use the bathroom, and Letty takes the little girl inside. Joe's mother Ava owns the motel and she agrees to let Letty and Maya rent an efficiency unit that has become a storage place for all the unwanted items from the motel.

Though Joe remains skeptical of Letty, Ava is friendly and quickly becomes affectionate with Maya. Letty knows she must begin creating some order in her life, including getting a job. However, she also needs to be with Maya. Ava comes up with the perfect solution by offering Letty a job at the motel. Letty can keep Maya close when she is working in the office. Isabelle, Ava's daughter, will watch Maya in the afternoons. They begin to settle into a routine though Letty is cautious. She knows that both the police and Tanya's former boyfriend Evan are looking for her and Maya. Joe soon learns the truth as well, but he instinctively feels there is more to Letty's story than meets the eye.

Evan is a successful businessman who has become rich from buying apartments that he uses as Airbnb rentals, though most of the apartments are in buildings that prohibit that practice. Letty had worked for him before Evan became involved with Tanya. Recently, Evan and Tanya have been locked in a messy court case because Tanya wanted to move to California. After her death, Evan learns that Tanya left a will leaving everything to Maya, which was a blow because he had put several valuable properties in Tanya's name as a tax dodge. Now, Evan needs Maya back and wants Letty dead. He believes he is working with a corrupt city official named Vikki Hill who can facilitate that, but Vikki is actually an undercover FBI agent.

Letty begins to discover more about Tanya's past, including that she stayed at the motel years earlier and was working with a couple of con men. Declan Rooney is actually Maya's father, but he does not know it. He and Tanya had bilked seniors out of an enormous amount of expensive jewelry before Tanya was arrested and Declan had to flee without the loot. As Vikki and Joe set up a sting to capture Evan, Declan is looking for the jewelry. He also realizes Evan has posted a $10,000 reward for Maya's return. He tries to kidnap Maya, thinking Evan will certainly pay more than that for her return. Maya escapes; Vikki and Joe arrest Evan; and, Vikki finds the hidden loot. Joe and Letty have fallen in love, but Letty feels the need to return to New York to handle Tanya's estate and Evan's trial. Once that is done, she and Maya return to Florida where she marries Joe.