Jason Sherman’s seriocomic The League of Nathans is an immensely entertaining play which, time and again, masterfully executes one of the great theatrical tricks: Sherman is an expert at allowing the prevailing comic tone of his play to give way and reveal the unexpected sadness and confusion hiding just beneath all the boisterousness. And the seam between the two moods is invisible.

The play concerns three men, all Jews, all named Nathan, friends from childhood when they would get together and hold raucous meetings of their secret club, the League of Nathans. They’ve grown apart as adults, though, and the play kicks into action when two of the Nathans – Abramowitz, a vaguely depressed writer, and Isaacs, his cheerful, motor-mouthed friend – are summoned to a reunion of the League in Spain by the third Nathan, Glass, whom they haven’t seen since he moved to Israel some 14 years ago.

Sherman does a deft job of juggling a fairly complicated series of flashbacks. On occasion, he’ll simply insert a single line of dialogue from years ago in the middle of a present-day scene – there’s a nice moment early on in the play when Abramowitz’s conversation with a fellow tourist on the airplane to Spain is naggingly interrupted by his memory of Glass and Isaacs below his bedroom window, calling him to another meeting of the League.

At the heart of the play, though, is Abramowitz’s search for what it means to be a “good Jew.” Every other character in the play has an answer for him, and it’s to Sherman’s credit that none of these characters winds up sounding like a mouthpiece. Most of them just seem puzzled that Abramowitz should even have to ask. There are several lovely scenes between Abramowitz and his grandfather, Zaydie, who assures him that he’ll just know instinctively how a good Jew behaves. But he lacks the instinct. And in Spain, when he re-encounters Glass, who has joined the Israeli reserves and challenges him to name one thing he has ever done to qualify himself as “good,” Abramowitz’s mind is a blank.

It’s a shattering moment, all the more effective for how disarmingly direct Sherman has been in leading up to it. And the questions it raises keep multiplying – what, in the end, are we all meant to do on this earth? What actions are we supposed to take to uphold the things we believe in?

Sherman has a great gift for comic dialogue. His ear is keen enough that he doesn’t need to rely on one-liners, as in the opening scene between Abramowitz and Isaacs, where Isaacs says Abramowitz isn’t treating matters with enough “seriousity.” Abramowitz tells him “SeriousNESS is a word. Seriousity is a malaprop.” “A what?” “A malaprop.” “Oh,” Isaacs responds, “like THAT’S a word.” You would think Sherman would be content to rely on his comedic talents and turn out a play that’s merely funny. But, like Abraham in the joke that Zaydie tells in the play’s first scene, Sherman turns out to have a lot on his mind.