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.

Alan Sepinwall has been reviewing television since the mid-'90s, first for Tony Soprano's hometown paper, The Star-Ledger, and now for HitFix. His new book, "TV (The Book)" about the 100 greatest shows of all time, is available now. He can be reached at