What happened in the dream?

I hadn’t been to the shooting location yet, but it looked like Harry’s house in the woods. I followed a 5-year-old girl wearing a tiara out to a pond next to the house, and she started to walk right into the pond. I went into the pond, too. Both of us were fully clothed. And there were two ducks at the far side of the pond watching us. I never dream about other actors or anything like that, but Keanu Reeves was also there, and I couldn’t figure that out. Why was he in my dream?

And then I remembered that Keanu had a very interesting response to a question in the past year, when Stephen Colbert asked him, “What do you think happens when we die?” Keanu took a breath, and then he said, pretty slowly, “I know that the ones who love us will miss us.” It was something about his demeanor, the profundity and the simplicity of his response. So I think that was why, because those issues about facing death are part of this season. Parsing all of that the next day was particularly valuable. It was like a crack of lightning over a dark valley — I could see the valley for what it was.

How so? And how did it affect your performance?

Everything you see is also something seeing you back. What are the ducks to you when they look back at you? So you start seeing this invitation to spontaneity, to be more playful, to be more willing to take this sense of connection to Harry’s journey. The girl is a reflection of some aspect of Harry. It brought a kind of heightened awareness. That was powerful in the framework, the fear of being seen that has always been part of Harry’s natural state.

“The Sinner” invited you into the writers room to help incorporate aspects of your personal life into the story in Seasons 1 and 2. Anything in Season 3?

In Season 2, we incorporated aspects of how my mother had a psychiatric illness and the consequences of unintentional abandonment. By this season, there was also Ambrose’s biophilia, I call it — the love of living things. The writers all know I have an exotic fruit orchard, so Derek said: “We slugged in this stuff. What would he say?” I used my own experience for the nursery scene where he’s like: “Don’t choose these. These are root-bound.” Planting the tree with Jamie is intimate. It allows them to get to the place where they can talk candidly.

Greil Marcus once wrote an essay called “Bill Pullman’s Face,” describing your face as its own landscape, a window opening into America as a “nihilist kingdom.” He said you look pushed down by the weight of a world that looks just as it did yesterday but no longer makes any sense.

[Laughs] Interesting. A recurring series does give incredible permission to recognize that there is so much more that can be seen, even when you’re not talking, you know? I was just talking to Derek about that. I said to him, “There seem to be a lot of people who enjoy not being told things verbally but sensing them in the stretches of silence.” Choosing takes is a matter of deciding when the subtext is enough. But the subtext is not just one color. Sometimes it’s the opposite, in the same moment.