PORTLAND — Mad Horse Theatre Company is presenting Austin Pendleton’s “Uncle Bob” as part of its Dark Night Series.

The reclusive Bob is an angry old man who has never done anything meaningful in his life. A failed actor and writer, he has driven away his loving wife. He is dying of AIDS.

Josh, an unemployed college dropout with his own baggage, arrives uninvited on Bob’s doorstep and declares he is there to take care of Bob.

A loving family reunion this is not. The visit is filled with name-calling and open scorn as the two men reconnect and discover, much to their chagrin, that they are kindred spirits. “Uncle Bob” boldly explores those perplexing questions about life and death that existential philosophers ponder endlessly.

The show, which opened Monday, runs through March 28. Performances are at 7:30 p.m. Monday, Tuesday and Wednesday at Lucid Stage, 29 Baxter Blvd. Cost is pay what you can, with a suggested donation of $10.