Bill Murray, Delaware actor in HBO mini-series

When Wilmington native John Gallagher Jr. saw an e-mail from his agent asking him to call, he had no idea there was really good news coming his way: Gallagher had snagged a role in the new HBO mini-series "Olive Kitteridge."

But Gallagher was a little too busy to call his agent back – he was in Los Angeles at the Season 2 premiere party for the HBO series "The Newsroom," which begins its third and final season Nov. 9.

"I'm at the premiere. I'm a little busy right now," thought Gallagher, 30, just before HBO programming president Michael Lombardo came up to him.

The only problem was this: Lombardo knew the good news and Gallagher, who also co-stars in "The Newsroom," didn't.

"He said, 'Congratulations, you did great. We think you're going to be perfect,' and I had no idea what he was talking about," says Gallagher. "I told him, 'Great. Me too. I'm so excited.' That's when I figured I should check my e-mail again and I learned that I got the part that day."

Thanks to that awkward, but satisfying moment, the Brandywine High School graduate will be seen alongside a trio of Academy Award-nominated actors – Frances McDormand, Richard Jenkins and Bill Murray – starting Sunday night in the four-hour mini-series, which will wrap up Monday night.

Even though Gallagher already has connections to HBO thanks to "The Newsroom," there was no overlap between the two jobs. "Olive Kitteridge" was produced by Tom Hanks' production company, Playtone, and Gallagher had a pair of auditions for the role.

Now Gallagher is ready to nearly take over HBO for the month of November thanks to the back-to-back airings of "Olive Kitteridge" and "The Newsroom."

"I didn't see that coming. I'll fix the lights, I'll mop the floors. I'll do anything for HBO," he says. "They are amazing people to work for. I'll do anything they ask me to, basically."

Before getting the part, Gallagher had not yet read "Olive Kitteridge," the 2008 novel by Elizabeth Strout that earned her a Pulitzer Prize. His mother and sister had read the book, an intimate collection of short stories based on the life of a Maine woman, but he was unfamiliar.

After starting the book, he eventually decided to put it down and let the mini-series' script be his source material because the book was "playing with my head." Once shooting of the mini-series was complete, he finished the book and was wowed like most of its readers.

"It really is a miraculous book. It speaks volumes to the human condition of having a family and all the ins and outs that go with it," says Gallagher, who filmed "Olive Kitteridge," last fall in the Boston area. "[Our writer and director] really brought that out and imbued the mini-series with a lot of humanity."

Gallagher, also a musician, is fresh from a Delaware visit last month to perform at the Open Space Music Festival at Bellevue State Park to support the anti-development Save the Valley campaign. His folk musician parents, John and June, still perform regularly in the area.

Gallagher has won a lead acting Tony Award for Broadway's "Spring Awakening" and has co-starred in other live New York productions like "American Idiot" and "Jerusalem." He has a debut rock album, "Six Day Hurricane," completed and ready for release, perhaps next year.

But even with his long resume, "The Newsroom" has given Gallagher more exposure than any other project. It wraps up a shortened six-episode final season with the series finale airing Dec. 14.

The controversial political/news drama wrapped in July with Gallagher and his fellow co-stars saying goodbye to characters they have lived with since 2012.

"Ideally, everybody wants it to run longer and be a success and a hit, but when you're doing a pilot, you feel lucky just to have it picked up and be seen," says Gallagher, who also stars in the recently released indie film "The Heart Machine." "So three seasons seems like a proper fit. And fans of the show are really going to like the final episodes. Aaron Sorkin tied everything up in a very neat and satisfying way."

In April, Sorkin apologized to an audience at the Tribeca Film Festival for the writing on the show's first two seasons, saying he would "like to start over."

Gallagher saw a change in Sorkin via the third season's script with a lot more attention paid to the characters and less to the news events that tend to swamp the fictional Atlantis Cable News network, which employs Will McAvoy (Jeff Daniels) as its lead anchor.

"The characters really take center stage," Gallagher says. "It becomes about their development and growth. It's very lofty to fit all of that in there for all those characters in six episodes, so it's very fast-paced. Something's always happening. There's a great energy and urgency behind it."

Even though "The Newsroom" will never be the long-running, beloved drama that Sorkin's "The West Wing" evolved into, Gallagher is thankful for the experience. After years on Broadway with small television and film roles, he can now fully appreciate the power of HBO, even before "Olive Kitteridge" debuts this weekend.

"It's incredible how powerful television is these days. After doing theater in New York for six or seven years, there's a different level of intrigue and interest when you find yourself on a HBO series," he says. "It's the most exposure I've ever had as an actor, without a doubt, and it fortunately comes along with getting more scripts for things on television or in film.

"It's nice having a little more recognition, although I'm not king of the world or anything. But there were doors that I used to have to pound on that now I only have to knock on. And in some very lucky scenarios, they just open."

-- Ryan Cormier, The News Journal. Facebook: @ryancormier . Twitter: @ryancormier . Instagram: @ryancormier .

IF YOU WATCH

What: "Olive Kitteridge"

When: Sunday and Monday, 9-11 p.m.

Where: HBO

IF YOU WATCH

What: "The Newsroom"

When: Sundays at 9 p.m., Nov. 9-Dec. 14

Where: HBO