My date and I were agreeing, before we ducked into the theater Under St. Marks (both its name and its location) that a modern one-act based on an ancient Greek text performed in a basement theater sounded like a recipe for a dreadfully boring evening.

“And then I saw that it was a musical, too” my friend added. “ And I thought: Could it possibly get any worse?”

How delightful it is when you are utterly wrong.

“The Persians: A comedy about war with five songs,” created by the Waterwell theatrical troupe, is indeed based on Aeschylus’ play of the same name, one of Western civilization’s oldest texts.

It is also a rollicking good time, a smart and funny and original entertainment with a political message, too.

Instead of presenting the text as written, the troupe’s four performers – Hanna Cheek, Rodney Gardiner, Arian Moayed and Tom Ridgely – take Aeschylus’ story and make it the basis for a series of production numbers that underline the play’s anti-war theme.

The opening scene plops the ancient Persian royal family into a TV sitcom. Later, when Darius (Gardiner), the former king of Persia, is called out from his grave by his despairing wife, he emerges as a James Brown figure vamping his way through the Janis Joplin classic “Cry Baby” – here, “Cry, Persia.”

(The revision is credited to the entire cast. This semi-improvisational take on traditional text is the hallmark style of Waterwell, founded by two 2002 University of Indiana grads who came to the big city to make it in show biz.)

Both the original “The Persians” and this re-imagining of it concern the mighty kingdom of Persia which – on the whim of its young king, Xerxes – leads an assault against Greece. The Persian army outnumbers its enemies, but is destroyed when the misguided king makes bad decisions based on faulty intelligence. Any resemblance to current events is, of course, purely coincidental.

But there’s no way that a written description can do justice to this cast’s blazing energy and inventiveness.

Cheek struts through the role of Queen Atossa with a nervous sex appeal, like a younger and sleeker Megan Mullally. (Elizabeth Payne’s costume design has all four performers opening the show in business suits and bowlers, but Cheek is quickly stripped down to pearls and a dress shirt belted with a tie.) Gardiner as her late husband Darius – and the show’s sometime emcee – carries his show-stopping number with aplomb, and delivers his one-liners with a soupcon of bracing anger. Ridgley as the Herald is almost the only cast member to perform pieces of Aeschylus’ actual text, and he performs this difficult task so well it melds seamlessly with the modern bits.

Moayed as Xerxes, however, steals the show. Moayed himself is a native of Iran (once part of the Persian empire), and he injects his cultural heritage into his performance. One of the most effective numbers – an original penned by composer Lauren Cregor – features Moayed singing in Farsi about the need for Persia to attack Greece, while Ridgley sings to the same tune, in English, about the need for the U.S. to go to war in the Middle East.

And Xerxes final monologue about the destruction of the Persian army – when the entire production suddenly becomes dark and foreboding – is also delivered in part in Farsi. It is unexpectedly, inexplicably moving, thanks to Moayed’s passionate delivery.

Praise is also due to Kate Mehan and Lynn Peterson, who choreographed each musical number (and the boxing match that, on this small stage, stands in for the battle between the Persians and the Greeks), and the orchestra, which consists of guitarist Jeremy Daigle, bassist Joe Morse, and two iPods working overtime.

Won’t you please go see “The Persians”? You will be marvelously entertained, I promise. And St. Marks Place is the new restaurant row, so you can do a fabulous evening out by combining the show with a good meal. (Make it a Middle East theme night and try the hummus place across the street.)

But most importantly, performances as daring and as thoughtful as “The Persians” deserve the sustained applause of full houses. I hope the Waterwell kids get it, because they certainly earned it with this show.