For many authors, being given a chance to write a bestselling series would be more than a dream—it would seem impossible. However, for author Marshall Karp, cocreator and writer of the NYPD Red series alongside the venerable James Patterson, that’s precisely what happened. “Patterson would never give away a series,” Karp said. “But I was with it since its birth, and so I think that’s what sets me apart.”

Karp first met Patterson in the late 1980s, back when Patterson was still working in the advertising business. Patterson had yet to begin building his literary empire and was seeking a freelance advertising consultant. Karp was working long hours in Hollywood, he said, when a headhunter called him out of the blue asking if he would like to do freelance advertising for Patterson. Karp remembers saying, “Who’s James Patterson?”

Today, Patterson needs no introduction and routinely has countless titles on the top of various bestsellers lists, produced under his own name as well as with collaborators, and all released by a team at his longtime publisher, Little, Brown. Karp and Patterson’s working relationship developed into a friendship, and one day Patterson called Karp, asking, “Want to write a book with me?”

Karp agreed, and, like many authors working with Patterson, received an outline, a 75,000-word quota, and a deadline. “Writers don’t pitch,” Karp said. “Patterson gives out the assignments.”

After finishing Kill Me If You Can, Karp found himself with the opportunity to pitch the idea behind NYPD Red. “It involved a special task force in New York City hired to investigate crimes happening to the rich and famous,” he said. Patterson liked the concept and tasked Karp with writing the outline. Just like that, they became cocreators.

NYPD Red follows the investigative adventures of detectives Zach Jordan and Kylie MacDonald as they work the eponymous NYPD Red task force, hired to protect the wealthy and the rich in the city that never sleeps. After approximately nine years and six books in the series, Karp and Patterson hit a snag. “He got really busy with other commitments,” Karp said, explaining that any new NYPD Red title wound up in the same pipeline of countless books Patterson produced with different collaborators. It became the biggest challenge and change for the series and for Karp.

“You write a book and it’s going to take up close to a year” before it could be released, Karp said. He explained that after a book was finished, it became increasingly likely that the NYPD Red series would wind up in the queue, behind books Patterson produces with figures such as Dolly Parton and Bill Clinton.

Eventually, Karp and Patterson had a meeting, which resulted in Patterson giving Karp his blessing to take over the series. “I was able to work out an arrangement to own the series,” Karp said.

The first Karp-led effort is the seventh installment, The Murder Sorority, set to be released in November by Blackstone Publishing. The biggest change readers will notice will be on the cover—rather than Karp and Patterson being listed as coauthors, Patterson provides a blurb for Karp’s solo effort.

Karp promised that despite the absence of Patterson as a NYPD Red contributor, readers will find familiar characters. “I don’t think there’s going to be any dramatic change to the series,” he said, noting that fans can expect more adventures with Jordan and MacDonald and even some different formats. A TV series and a YA entry might even be in the works.

“I feel better about being able to get the next book out faster,” Karp said. “Now I can get NYPD Red to the fans front and center.”