In NYC off-broadway play called 10K, a man and a woman meet while stretching at a park and go for a run together. The actors run in place for almost the entire show, trading secrets and fantasies.

Mr. LaBute, who also directs, has the actors jogging in place at a fast clip, feet slapping the stage floor, breasts and pecs bouncing. That Ms. Alsip and Mr. Kandel should manage to speak the lines without panting or collapsing seems sufficient accomplishment. That they can convey character at the same time really deserves applause.

"The men in Mr. LaBute’s morally complex “The Mulberry Bush,” like Peter and Jerry in Edward Albee’s classic one-act “The Zoo Story,” are strangers in a park. Their meeting is not accidental, though it appears that way at first to quiet, distinguished-looking Bill (Victor Slezak), who often eats lunch on a secluded bench. Younger and seemingly lower-class, Kip (J. J. Kandel) has come to accuse Bill — to specify the charge would be a spoiler — and defend his own family."

The most nastily satisfying of the bunch is LaBute’s “The Furies,” which unfolds within a self-contained single scene.

Barry (Victor Slezak) has some bad news for his sullen younger lover, Jimmy (J.J. Kandel). He’s facing two people instead of one, though: Jimmy brought his sister, Jamie (Alicia Goranson), to the lunch meeting. “For backup,” he explains. “In case you get all weird on me here.”

It may be an old formula for a one-act: start with a life-or-death moment, spend your 20 minutes explaining how it came to be, while the constant threat of a concluding gunshot keeps the tension high. But Mr. Sosko and J. J. Kandel as the jittery gun-wielder play it convincingly.