A conventional ghost story would've been far less unsettling. Over the course of a few loosely plotted scenes, Shining City offers frightening insight into people haunted, both literally and figuratively, by varying combinations of ghosts, guilt, loneliness, and dread. The play — written by Irish wunderkind Conor McPherson and making its West Coast premiere at SF Playhouse — concerns a Dublin businessman (Paul Whitworth) who begins seeing a therapist (Alex Moggridge) after his wife dies in a car accident. McPherson's script is so subtle and so dependent on intricately constructed monologues that it would've been unbearable in the wrong hands. But here, directed with perfect restraint by Amy Glazer, the play quietly creates a world convincing both in its humanity and its bleakness, with patient and therapist mirroring each other's isolation and grief. And while the cast is strong, the greatest credit should go to Whitworth, who masterfully delivers a monster of a monologue that serves to anchor the rest of the play. Shining City generates enormous energy in slowly revealing its characters' failures and fears, and the play's final moment elicits something awfully rare in live theater — audible gasps. It's an ending liable to leave you as haunted as the people onstage.