The Guthrie Theater has "A Christmas Carol," and Penumbra has "Black Nativity" — shows that return every year and have become beloved family traditions. Is History Theatre joining that roster with "Glensheen"?

Since its premiere in 2015, the Chan Poling-Jeffrey Hatcher musical comedy has proved immensely popular, selling out runs at the St. Paul playhouse. The show, about a bungled burglary that led to a double murder at the Glensheen mansion in Duluth, is based in part on news stories by Minneapolis Tribune reporters Joe Kimball and Peg Meier.

On June 27, 1977, there was a break-in at the 39-room Jacobean mansion of the 83-year-old Duluth mining heiress Elisabeth Congdon.

The intruder first encountered her night nurse, Velma Pietila, and killed her with a brass candlestick. Congdon, in her bed, became the next victim. She was smothered with a satin pillowcase.

Her adopted daughter Marjorie Caldwell and son-in-law Roger Caldwell were both charged in the killings. Roger was convicted in 1978 but Marjorie was acquitted the following year. He would later commit suicide, but maintained his innocence in a note.

"The old mansion, the crashing waves — it has all the elements of a great Agatha Christie mystery," Hatcher said. "Or it's like an episode of 'Colombo' rewritten by the guys who did 'Fargo.' "

"Glensheen" opens Saturday for its seventh run. The fascination with the notorious case has not waned. We talked to the actors and creative team about why the musical has struck such a nerve.

The shock of it: "The case was literally ripped from the headlines and the trial was the trial of the century in Minnesota," said director Ron Peluso. "Elisabeth was Duluth royalty and one of the richest people in Minnesota. She lived in this great mansion. Everybody was curious about her and her life." Then to have her die like that was confounding to many.

Compelling book and music: Peluso has staged a compelling production that realizes both the comic potency and the pathos of Hatcher's airtight book. And Poling's songs, arranged by Robert Elhai, who also worked on "The Lion King," are clever, funny and sad with oving melodies and catchy hooks.

"When Thelma the nurse is singing her song, the countermelody of the cello is like the voice of the husband," said Dane Stauffer, who plays Roger. "It works on your soul and makes you want to cry."

Kills with laughter and honors victims: "Jeff and Chan pieced together a brilliant piece of work that's wickedly funny and in gentle ways, honors the lives of those two women who were murdered," Peluso said. "People find that refreshing and entertaining."

Hatcher recalled that in one of the early workshops where the company performed the nurse's song, there was a family member in the audience — Pietila's grandniece.

"It was a snowy night in St. Paul all those many years ago, and she was moved by the song. That told us we were on the right path," he said.

A unexpected connection: "We use the word problematic to describe plays or characters like Mama Rose, Richard III, or Troy from 'Fences,' " Hatcher said. "People wrestle with what would they do in any given situation. Marjorie is weirdly identifiable to our audience for as much as the real Marjorie is a villain, our Marjorie is charismatic and beautiful. And when you have people like Jen [Maren, who plays Marjorie] and Dane [Stauffer, Roger] who have this great connection to the audience, no matter the terrible things they do, the audience is willing to go along with the journey."

ID'ing with Marjorie: The heiress, who was accused of planning the crime as a way to speed up her $8.2 million inheritance, is especially relatable to women and gay men, said Maren, who delivers some of the show's signature numbers.

"'The Torch Song' is about a woman of a certain age being invisible. And the older I get, the more I relate. You just disappear in society," she said. "I find gay men are loving her because she's this big, broad bombastic character with a lot of anger but she's also charming and funny."

From amorphous to clear: We have a desire for order and understanding, and that's especially true when we have gaps in knowledge or memory.

It's rewarding to have "something that's haunting, amorphous and indistinct turned into something solid," Hatcher said. "This not only solidifies the story for people but also helps them understand their own personal history."

No sense of closure: There were murder charges, trials, a conviction, an acquittal and a plea bargain. Even though the case was closed in the courts, it was not in public opinion. Questions are still being raised about the motive and the murders.

"Of course, we don't know who actually committed the murders," Peluso said. "Roger Caldwell, when he took his life, said in his note that he didn't kill those girls. And Marjorie still lives in Tucson, where people can find her walking her dog."

'Glensheen'
Who: Composed with lyrics by Chan Poling. Book by Jeffrey Hatcher. Directed by Ron Peluso.
Where: History Theatre, 30 E. 10th St., St. Paul.
When: July 8-23: 1 & 7:30 p.m. Thu., 7:30 Fri.-Sat., 2 p.m. Sun.
Tickets: $50-$74. 651-292-4323 or historytheatre.com.

Correction: Previous versions of this story misspelled the last name of Robert Elhai.