The So Far Theatre Company doesn't go nearly far enough with its production of "Grandma Duck Is Dead," now playing at the Source Warehouse Rep through March 16.

The first comedy written by the late Larry Shue, this long one-act suggests the off-the-wall merriment, the nutty wordplay and, yes, the gravity behind the grin that came to flower in Shue's best full-length work, "The Foreigner." But the So Far production is so unadventurous and the actors so restrained that the evening comes to naught.

I think I know what the root problem is: Director Jim Mumford wants to show us that Shue was more than just a gifted screwball and that this account of three college cut-ups indulging in one last round of pranks has something sobering to say about growing up. In its pursuit of the "serious" subtext, however, the production fails to exploit the obvious zaniness on the surface. This "Grandma Duck" is no fun at all -- an inexcusable sin, given the opportunities that Shue has lavishly provided.

Woody, Ben Davidson and Badger have spent their college years hiding out in a world of hare-brained fantasy. Before graduation sends them out into the work place -- or worse, the Vietnam battlefield -- they cook up one last mad scenario. They will hypnotize Tim Esperanza, a willing black musician, and convince him he's really Ringo Starr. When Esperanza threatens to trip out completely, however, the wits are momentarily drawn up short and have to ask themselves if the nonstop games of their youth have been more lethal than they imagined.

What you need to make this charade work is a cast of inspired, slightly surrealistic comics -- along the lines of Robin Williams, I suspect -- who just seem to combust spontaneously. But the So Far actors -- Mark Silence, Joseph B. Musumeci Jr., Michael John Lindsay and Tony Perkins -- are too inhibited to be even mildly amusing. Their giddiness is forced, their repartee self-concious. As the coed who calls them on their childishness, Monica R. Lijewski seems to be doing well just to spit out her lines.

Musumeci has designed the appropriately ramshackle dormitory room that houses the high jinks, but Mumford uses the set unimaginatively, bunching his actors in tight, static clusters. After a while, the whole sophomoric affair reflects badly on the script, which begins to look pretty foolish, too.

That's not fair. Granted, "Grandma Duck" may be a minor effort. But you can still sense in it a playwright, poised and ready to go into orbit. Weighed down by too many good intentions, perhaps, the So Far Theatre Company never gets off the launch pad.

Grandma Duck Is Dead, by Larry Shue. Directed by Jim Mumford; set, Joseph B. Musumeci Jr.; lighting, Marianne Meadows; costumes, Susan Alison. With Michael John Lindsay, Mark Silence, Tony Perkins, Monica R. Lijewski, Joseph B. Musumeci Jr. At the Source Warehouse Rep through March 16.