What do you call cheaters whose shadiness also makes them murder suspects?

Rodents and insects, according to Agatha Christie.

The world's best-selling fiction author doesn't quite come out and say humans who step out on their spouses and partners are vermin. But she implies that in the titles of "The Rats" and "The Wasp's Nest," two murder-mysteries with romantic entanglements at their center.

The theatrical double bill kicks off the 16th season of Osseo's Yellow Tree Theatre.

"We love mysteries and these two are super-entertaining," said director Austene Van. "There's a reason Agatha Christie's books are second only to the Bible in terms of popularity. They are filled with wit and humor, and these characters have great personality."

Far less popular than Christie's most-produced drama, "The Mousetrap" — a play in which she also implicitly throws shade on humans — "Rats" premiered in 1962 as part of Rule of Three, a collection of one-acts. It orbits two adulterers, Sandra and David, who have been invited to an apartment for drinks only to find themselves trapped like, well, rats.

Sandra's husband has been thrown off a cliff. Did she do it? The illicit lovers are locked inside the apartment.

Christie's famed detective Hercule Poirot appears in "Wasp," and finds himself in the middle of a love triangle as he tries to prevent a murder.

Van directed both "Rats" and "Wasp" in 2019 at St. Paul's Park Square Theatre as part of a Christie triptych that included "The Patient." That third play is not included in the Yellow Tree package for a simple reason: budget.

"We couldn't afford 'Patient' because there are about 10 people in it," Van said. "It's a time to be frugal."

The two shows that the theater is presenting have smaller casts, which means that they can go up in a shorter rehearsal time. The double bill also is compact in a way that heightens the potency of both the mystery and the humor.

"They're quick and fast-paced, but that pacing doesn't allow you to get ahead of the story," Van said.

Veteran Twin Cities actor Charles Fraser, whose three decades on the stage has taken him from the Guthrie and Jungle theaters to shows on cruise lines, plays Poirot. He previously worked with Van in "The Royale," also at Yellow Tree.

Other members of the cast are new to both the director and the theater that has brought high quality works to Minneapolis' northwest suburbs. The ensemble is rounded out by singing actor Tara Borman; Paul LaNave, who was in "Trayf" at Six Points Theater and played Romeo at Park Square; Maggie Cramer, whose credits include the Jungle Theater's "Georgiana & Kitty: Christmas at Pemberley"; and Christopher Kehoe, who has performed classical and contemporary roles across the country.

Van said that one of the attractions of Christie's work, both on the page and the stage, is the fact that everyone in a story is a suspect.

"The plays present these characters as fully human," Van continued, even if they are likened to animals and cretins. "No one is all bad or all good."

'The Rats' & 'The Wasp's Nest'
When: 7:30 p.m. Wed.-Sat., 2 p.m. Sat. & Sun. Ends Oct. 29.
Where: Yellow Tree Theatre, 320 5th Av. SE, Osseo.
Tickets: $40. 763-493-8733 or yellowtreetheatre.com.