A New Yorker through and through, Mr. Plepler intends to provide series and movies for the Cupertino, Calif., company from the second floor of a townhouse on Manhattan’s Upper East Side, which he has been using as his office since August. On a mirror is a taped sign of a Ted Williams quote that he has carted to nearly every office he has inhabited in his long career: “Don’t ever let anyone monkey with your swing.”

Mr. Cue contacted Mr. Plepler soon after his abrupt departure from HBO.

“As you can imagine, in the days and the first couple weeks after I left, I received an enormous amount of well-wishing calls, and Eddy was among those people,” Mr. Plepler said. “He was generous enough to say on that call, ‘Look, when you settle down and you think about whatever it is you want to do, know that we’re all here and we’ll talk.’”

In July, Mr. Plepler had a meeting scheduled with Mr. Cue at the Allen & Company Sun Valley conference, an annual gathering of media and technology executives. He planned to broach the idea of producing for Apple, but only if Mr. Van Amburg and Mr. Erlicht were on board.

The week before the Sun Valley trip, Mr. Plepler had lunch with the two Apple TV Plus executives at the Mark Restaurant, an Upper East Side power-lunch spot at the Mark Hotel run by the chef Jean-Georges Vongerichten.

“If they weren’t responsive,” Mr. Plepler said of Mr. Van Amburg and Mr. Erlicht, “I didn’t want to pursue the conversation. And they could not have been both more generous and more enthusiastic. So that was my first conversation. And I followed that up with Eddy in Sun Valley, and we started putting this together.”

Mr. Van Amburg said he and Mr. Erlicht welcomed the addition of Mr. Plepler to Apple TV Plus.

“Jamie and I ran a studio for years, and we know how exciting it is to produce and start businesses,” he said. “We have a longstanding mutual admiration with Richard, and we’re looking forward to helping him build a dynamic production company and seeing him thrive with us at Apple.”

One topic Mr. Plepler did not want to discuss in detail: his exit from HBO.

“New people came in and bought the company,” he said. “And it was just the right time for me to go on to the next chapter in my life.”