James is cast after a chemistry test with Woodley. Producer Doug Wick:
We didn’t know much about him, just his one memorable appearance on Downton Abbey. He is doing the same scene with Shai that she’s done with dozens of other actors. But Shai always plays it full out. Theo is smart, observant, and incredibly handsome. He has a wryness, a sense of humor. It adds a layer to all the scenes. He plays off Shai’s power. He has plenty of his own intensity. They are electric together. Even when Theo’s quiet, you wonder what he’s thinking about. He’s got that movie star thing… Just in the nick of time, I think we have our Four.