Oceanside author Stephanie DeCarolis set to release "The Perfect Sister"

Oceanside resident Stephanie DeCarolis is ready to captivate readers with her latest psychological thriller, “The Perfect Sister,” slated for release by Ballantine Books on July 16. The book delves into the mysteries surrounding a young woman’s disappearance in the Hamptons.

A lifelong resident of Oceanside, DeCarolis, 38, initially pursued a career in law, specializing in medical malpractice. But her passion for writing eventually led to a career change. Her journey to becoming a bestselling author is as intriguing as the plots of her novels.

“Writing has always been something I loved, and it was sort of a hobby for me,” DeCarolis said. “It was a hobby that I fell back into after having my two daughters. I had taken a step back from my career. If I was ever going to write a book, now was the time to do it, before I went back to work full-time.”

Her leap of faith paid off: Her debut novel, “The Guilty Husband,” published by Ballantine, a division of Random House, in 2021, became a USA Today bestseller. She followed it with “Deadly Little Lies” later that year, quickly building a reputation in the genre of suspense.

“I got very lucky that first book that I wrote ended up being picked up by a publisher, and I’ve had a lot of success with it,” DeCarolis said. “Now I’m extremely fortunate that I get to do this full time.”

“The Perfect Sister” is her third novel, and she considers it her best work yet. The story follows a woman as she investigates her sister’s mysterious disappearance while working a summer job for a wealthy Hamptons family. The book explores themes of sisterhood, family dynamics, and the lengths one will go to uncover the truth.

“When I was a kid, my parents used to take me to Montauk every summer,” DeCarolis recalled. “That’s a tradition that I still keep with my husband and our own kids. Driving through the Hamptons, seeing those grand houses behind gates, I couldn’t help but wonder about the secrets they might hold. That curiosity was the seed for this story.”

One of the hallmarks of DeCarolis’ writing is her ability to create complex yet relatable characters. “The Perfect Sister” features a mix of personalities, and she says it includes characters readers will love and others they’ll love to hate.

“I really love to write a good villain,” she said. “In this book, there are a few of them. A lot of character development went into this particular book, giving them all a back story so that you understand why they act the way they do and why they are the way they are. And that’s something that I think readers will be really excited about.”

DeCarolis credits her love for thrillers to their edge-of-your-seat excitement. “Lucy Foley has been a big influence on my writing,” she said, referring to the author of such books as “The Paris Apartment” and “The Hunting Party.” “She’s another author who is phenomenal at writing these first-person, multiple-first-person perspectives, where she incorporates dual timelines, and I think her writing kind of had a big influence on mine. I’m also a really big fan of Lisa Jewel and her mystery writing or thriller writing. Within the thriller genre, I read as much as I can, and cast as wide a net as I can. I think there have been so many books that have inspired me to want to write my own, and have had an influence on my growth and progression as a writer.”

Beyond her writing, DeCarolis is an active member of the Oceanside community. She frequently collaborates with the library, taking part in book club discussions and author talks. In recognition of her contributions, the Friends of the Oceanside Library presented her with the library’s Founder’s Award in March.

“It was a very nice surprise,” DeCarolis said. “The library did that as kind of a thank-you for my contributions to literature and working with them so much. I meet with their book clubs, and I’ve come in and done author talks. They’ve been so supportive since I started my writing journey, and I’m excited to continue that.”

To celebrate the launch of “The Perfect Sister,” DeCarolis will participate in a book signing at Beginnings Restaurant, in Atlantic Beach, on July 18 and another, at Book Hampton in East Hampton, on July 27. She is also planning an event with the Oceanside Library later this fall, coinciding with its grand reopening after its three-year renovation project.

Looking ahead, DeCarolis has more thrilling tales in store. She has signed a multi-book deal with Ballantine.

“It’s been such an amazing kind of whirlwind experience,” she said. “I know how difficult it is to get a shot in the world of traditional publishing. It is so hard to have a book be noticed, and there’s so much luck that goes into it. You have to find the right agent who can connect you with the right publisher. I got very lucky that my first book ended up with a traditional publisher, and that it ended up being as successful as it was, and it’s now set me up with a career that I can do full-time. It’s something that I don’t take for granted. I wake up every day saying, wow, I can’t believe that this is my actual job.”

“The Perfect Sister” is available for pre-order on Amazon and other major retailers. While details about which stores will stock the book are still being finalized, readers can be assured that both digital and hard copies will be widely available.