Guilt and mourning intertwine in Kevin Elyot's unsettling new play, Mouth to Mouth, now being presented by The New Group at Theater Row. In the opening scene, grief almost palpably hangs in the air as Frank (David Cale), a gay male writer, talks to his friend Laura (Lisa Emery), who smokes and says nothing. The following scene makes a small jump back in time, as the HIV-positive Frank meets with his doctor and friend Gompertz (Andrew Polk). There's something on Frank's mind, a guilt that he wants to unload, but the play reveals its mysteries slowly, and we don't find out what that is until the play goes even further back in time.

It's a year prior, when Frank is a guest at Laura's home, at[...]