Alex Kingston as Professor River Song in BBC's Sci-fi Tv Drama " Dr Who"

Alex Kingston, the beautiful English actress who become world famous as Dr. Elizabeth Corday in NBC's "ER" has once again charmed audiences with her brilliant performance in BBC's longest-running sci-fi television drama "Dr Who". Alex Kingston appears in eighth and ninth episodes of season four of "Doctor Who" as archeologist professor named River Song.

Alex Kingston gave a magnificent performance in two episodes "Silence in the Library" and "Forest of the Dead" of "Dr. Who" as Professor River Song. The episodes are set in the 51st century. In "Silence in the Library", other characters Doctor and Donna come to a planet-sized library which was sealed off 100 years earlier. The twosomes discover that the world is just deserted except for Professor River Song and her team who were on archeological expedition trying to discover why the century-old library is sealed off 100 years earlier.

In the following episode, "Forest of the Dead", Alex Kingston as Professor River Song sacrifices her life and dies to save the lives of the Doctor, Donna, and the 4,022 people trapped in the data core of the library.

Indeed Alex Kingston was at her natural best as Professor River Song in both the episodes which won her accolades from the critics and her fans.

The other stars in the British show "Doctor Who" include David Tennant as The Doctor, Billie Piper as Rose Tyler, Paul Kasey as Cyber Leader and Freema Agyeman as Martha Jones.