Playwright: Simon Block, adapted from Jonathan Safran Foer's novel. At: Next Theatre Company, 927 Noyes St., Evanston. Tickets: 847-475-1875; www.nexttheatre.org; $30-$40. Runs through: March 31

Improbable Frequency

Playwright: Arthur Riordan (book and lyrics), Bell Helicopter (music). At: Strawdog Theatre Company, 3829 N. Broadway. Tickets: 1-866-811-4111; www.strawdog.org; $28. Runs through: March 31

Everything Is Illuminated and Improbable Frequency have little in common except references to Nazism and an infectious theatricality—well beyond common-place realism—that successfully lures in audiences.

Everything Is Illuminated is a stage adaptation of Jonathan Safran Foer's award-winning 2002 novel in which a twenty-something American Jew, named Jonathan Safran Foer, visits the Ukraine to search for the woman who saved his grandfather from the Nazis. He is (mis)guided by Alex, a twenty-something Ukrainian translator, and Alex's not-really-blind grandfather and car driver. The book employs multiple narrative techniques, partly fiction, partly memoir-like, and partly a novel-within-a-novel. To his credit, British stage adapter Simon Block retains, but simplifies, the three main narrative lines and their levels of realism. Boiling things down to six actors and six main characters, Block retains the distinct linguistics of each narrative line and preserves the profundity of the work.

In a variety of ways, this work explores the Old Testament injunction about sins of the fathers (or parents, more broadly) being visited upon their descendants, a notion which the Greeks took up rather thoroughly in numerous tragedies. The corollaries of sins, of course, are choices, sometimes made under duress to save or protect others. What are we prepared to do or say? How will others see us who were not there in that moment? Very soon, Alex (who also narrates) emerges as the hero of the principal storyline and his grandfather as the antagonist.

This sounds solemn, but the story spins out with a good deal of humor as staged by Devon de Mayo and performed by a cast mainly of Chicago veterans. Tall Alex Goodrich dominates as Alex, swinging both ways—meaning from solemn to silly—with ease and confidence. William J. Norris as Grandfather takes potent advantage of his Act II opportunities after playing his standard curmudgeon in Act I. Everything is Illuminated even has moments of whimsy, such as an unseen (but heard) dog named Sammy Davis Jr. Jr. Grant Sabin's scenic design of three enormous shadow boxes, filled with the flotsam and jetsam of life present and past, provides an evocative presence for the swirling narrative lines and changing elocution.

If Everything Is Illuminated occasionally borders on whimsy, Improbable Frequency is pure whimsy from start to finish. This witty Irish chamber musical is set in Dublin in 1941 and concerns a British linguistics expect sent to decipher a coded mystery involving an improbable radio DJ (Meehawl O'Dromedary, a name conjuring camels and mules), the weather and a mad Nazi scientist who invents PAT, the "probability adjustment tank."

You need to know is that the Irish were forced to fight for the United Kingdom (of which Ireland was not-by-choice a part) in World War I, but by World War II the Republic of Ireland had been established. As partial payback, the Irish Free State remained neutral during WWII and bristled with anti-British sentiment, while the Nazis coveted its port cities on the Irish Sea. But forget all that. What happens is that the English spy falls for a fair Colleen who may be a spy herself, and the Nazi scientist is more Nutty Professor than threat.

It's tough to figure out much more than that in this rapid-fire, pun-filled, lightweight musical, performed with tongue firmly in cheek by a versatile troupe of six under director Kyle Hamman, choreographer Brigitte Ditmars and musical director Mike Pryzgoda, whose four musicians play 15 instruments (among them, flute, piano, guitar, violin, string bass, accordion and Irish drum). All six cast members are engaging and capable, but special kudos to Jason Grimm for his rubbery song-and-dance antics.

There's plenty o' Irish charm, just in time for St. Pat's Day.