Basing a play on a historical figure is always tricky. An audience member's likelihood of enjoying such a show is directly related to his or her familiarity with, or interest in, the subject, and for those who need to be convinced, the more exciting that person's life the better. What to do, then, with an only moderately famous subject who, despite some great achievements, made astonishingly little history?

That's the dilemma facing Joanna McClelland Glass with her play Trying, which just opened at the Promenade after a successful engagement in Chicago. Her subject is Judge Francis Biddle (1886-1968), who served as attorney general under President Franklin Roosevelt and later was one of the judges on the Nuremberg Trials. (Don't worry - if you've never heard of him, you're excused.)

All the more incentive for Glass to write this play: She's uniquely qualified, as she served as Biddle's secretary during the last year or so of his life, and got to know him in a way that few others did. She would seem an ideal choice for bringing out the man behind the public image, exposing his humanity, and making him interesting to potential audiences, no doubt hoping that we would eventually grow to understand Biddle, as she did, warts, eccentricities, and all.

Those warts and eccentricities are on very visible display here. Biddle, as played by Fritz Weaver, has been burned - literally and figuratively - by a number of bad secretaries; he has little patience for anything new, whether a secretary or a Dictaphone; he's a strict grammarian; he insists that only he be allowed to operate the antiquated gas heaters in his over-the-garage office; and, as he's in his early 80s, he's slowly losing control of his faculties.

Biddle and Glass's onstage persona, Sarah Schorr (Kati Brazda), initially clash, though she slowly gains his trust, confidence, and even respect as the days, weeks, and months pass. By the time the end arrives - Biddle states from the very beginning of the play that he knows he's living his final year - they've come to care for each other in a very special way: He's the loving father she never had, she's the firm, kind, and organized assistant he's long needed.

This is not a show heavy on story; it's composed almost exclusively of character moments. As Biddle corrects Sarah's grammar and Sarah attempts to deflate his Ivy-League expectations and prejudices, the two work on a number of projects involving dictation (Biddle is writing a book of his own and frequently assisting others with their writings about FDR), and bicker constantly about the heat of the room, and a number of other mostly minor matters.

The vastly majority of Glass's observations about Biddle, at least as presented in the play, are external; she never really succeeds in piercing his outer shell. Glass obviously still harbors feelings for the real Biddle, and has painted a delicate, loving portrait of him here, though she's done most of her work from the outside in and not quite reached his core. We learn much about Biddle's career, positions on a variety of subjects, and his personality, but far less about who he is underneath. With practically no plot to fall back on, Glass can't create enough dramatic build-up to make the final scene as touching as she intends it, and dramatizing only five mostly benign scenes in their relationship together doesn't help.

Still, Glass's love for Biddle shines through and, as sensitively directed by Sandy Shinner, the production never lacks for charm or warmth. The talent and likeability of the performers helps a great deal, and the two have a winning chemistry together: Weaver crafts a memorably lovable curmudgeon, and gives an impressive physical performance as the increasingly enfeebled Biddle, while Brazda has just the right youthful brashness for her role to provide a stark, colorful contrast. Jeff Bauer's cluttered office set, Carolyn Cristofani's costumes, and Jacqueline Reid's lights nicely complete the atmosphere.

The atmosphere is vital in helping the show feel like a warm embrace from an old friend throughout. And even when the show is bogged down in biographical or superficial data, Glass's affection for Biddle prevents Trying from ever being, well, trying. If the play is ultimately more effective as a personal tribute than a dramatic presentation, it's also a gentle, amiable reminder of how to best appreciate those who influence our lives in ways both great and small.

Trying
Promenade Theatre, 2162 Broadway at West 76th Street
Running Time: Running Time: 2 hours, 20 minutes with one intermission
Tickets online and current Performance Schedule: Telecharge