He did “Nassim” on a Wednesday evening, showing up after an “All My Sons” rehearsal looking slightly disheveled and appearing bemused as he awaited instructions hidden in a box on a table on the stage at New York City Center. (The show continues there, with various performers, through April 20.) Edited excerpts from a conversation follow.

What were you expecting?

Nothing. I’ve done a lot of improv; I’ve worked with TJ and Dave; and I guess I had an expectation that I would be taken care of. I couldn’t imagine anybody was going to throw me on stage to humiliate me or let me flail, because that wouldn’t make for a very good show.

Did you get any instructions?

Stage management sent me a little note a few days before the show that told me what stage door to arrive at, and said when you read a question, feel free to answer it, and if a word is written in all caps, stress it. They did not tell me what to wear. They did tell me to take my cellphone with me, but to put it on airplane mode.

What were you thinking as the show unfolded?

I’m a weeper, and I did think to myself, somewhat early in the proceedings, that I might have to steel myself, because I don’t want to start crying. They told me later some performers do.

What about it made you think you could cry?

In the time we’re living in right now, most people I know walk around trying not to cry most of the time. And the show touches on a lot of things — storytelling, language, transcending borders, connection — and connection with anybody is moving.