As I explained yesterday, the new season of "Doctor Who- the first one to air day-and-date in both American and the UK, and the first to feature filming on location in America - debuts on BBC America on Saturday night at 9. And last week, I went to BBC America's New York offices to interview Matt Smith, Alex Kingston and Karen Gillan. I posted the Smith interview in two parts yesterday, and Gillan will be posted tomorrow.

Today, though, it's Alex Kingston's turn. She's not a regular castmember, but producer Steven Moffat has made her time-traveling archaeologist character River Song just as important as the ongoing companions - in some ways more, since River and the Doctor have such a complicated, and possibly intimate, relationship.

In part 1 of the interview (part 2 is here), Kingston and I talk about how it felt to film in Monument Valley, at what stages she's learned things about River and the Doctor's relationship that even Smith doesn't know, and more.