‘Best Medicine’ First Look: See ‘Doc Martin’s Martin Clunes as Josh Charles’ Father (PHOTOS)

Welcome to Port Wenn, Doc Martin — and no, not the one played by Josh Charles on Fox’s cozy dramedy. Rather, Martin Clunes, who played the titular doctor on Doc Martin, the British series on which Best Medicine is based, is guest starring as Dr. Martin Best’s father, and TV Insider has an exclusive first look at father and son together.

Clunes pops up in the Tuesday, March 3, episode, aptly titled “Doc Martin.” He plays Dr. Robert Best, and Judith Ivey plays his wife, Vanessa. In the episode, Fox teases, “When Martin’s parents make a surprise visit, Martin suspects that his father, Robert, after blindsiding his sister Sarah [Annie Potts] with some infuriating news, is experiencing a serious health condition. Also, while trying to avoid the school’s forthcoming closure amidst its annual Spirit Week sleepover, Louisa [Abigail Spencer] is made acting principal and Martin and Robert must operate together on Mark [Josh Segarra].” Check out photos of Josh Charles and Martin Clunes as Dr. Martin Best and Dr. Robert Best below.

Fox

When Clunes’ casting was first announced in October 2025, Robert was described as “an accomplished, headstrong gastroenterologist whose abrasive demeanor makes Martin look practically cozy by comparison. Estranged from his sister Sarah, Robert’s surprise visit to Port Wenn puts everyone on edge. But underneath his snobby, stone-cold exterior, he’s hiding a few secrets of his own… that could turn Martin’s new life upside down, and force him to confront his past.”

Clunes starred Dr. Martin Ellingham for 10 seasons of Doc Martin (from 2004 to 2022). At first, the plan was just a hope to have him make a cameo, executive producer Liz Tuccillo told us.

“It was sort of a gradual decision of like, ‘Oh, wouldn’t it be nice to have Martin Clunes come in for a cameo?’ and then it was like, ‘Why just a cameo?'” she shared. “Then the natural idea came of it being his father, and we just couldn’t believe that he said yes. We were just so beyond thrilled. Everybody was beyond thrilled.”

Josh Segarra echoed that when he stopped by our offices to talk about the show earlier this season. “I think that they wanted to be respectful and say, ‘Hey, we just need you to come for a day and maybe pop in this one scene,’ and he said, ‘No, what you talking about? I want to play with you guys. I want to come and be there,'” he recalled. “To me, that says everything you need to know about Martin, that he wanted to come and really be a part of it with us.”

Related

'Best Medicine' Season 2: Cast, Premiere Date, More Details

Josh Charles called it “an absolutely joy” to have Clunes guest star. “He was a blast. I think he was really excited to be there, and I know I can speak for everyone there, we were really thrilled to have him. He was a great asset and just brought great energy and he’s super funny, and we loved having him.”

As for what to expect from father and son, “they are more alike than they are different, and that is the source of their conflict,” Tuccillo previewed. “That it really is an episode where we really talk about the past and sort of delve into his past.”

Added Charles, “[Martin’s] dynamic with his parents is tricky. It’s rife with a lot of conflict. It’s a particular dynamic for sure.”

Fox

Potts pointed to her work with “the very, very darling and hilarious” Clunes and Ivey (whom she’s been friends with for 50 years) as something she particularly enjoyed about filming this season. So far, we know the siblings’ relationship is tense just from Sarah’s “your damn father” to Martin in the series premiere.

“His parents are just awful. I mean, no surprises there. Anybody who has that many spikes all over them, it’s like hurt people hurt people. And, clearly, he’s been damaged,” she said.

What are you hoping to see when Martin Clunes guest stars on Best Medicine? Let us know in the comments section below.

Best Medicine, Tuesdays, 8/7c, Fox