Question: What actor appeared in the CBS television series "Knots Landing" and the movie "Sweet Revenge"?
Context: Valene "Val" Ewing (maiden name Clements, formerly Gibson, Waleska), portrayed by Joan Van Ark, is a fictional character in the CBS primetime soap opera "Knots Landing", a spin-off from the long-running series "Dallas", in which she also appeared.  The character originated on "Dallas" in 1978 as the mother of Lucy Ewing and ex-wife of Gary Ewing (the second son of oil baron Jock and Miss Ellie Ewing).  Van Ark made several guest appearances on "Dallas" before becoming one of the main stars of the spin-off "Knots Landing" in December 1979, though she continued to make small appearances in "Dallas" for the next several years.  Van Ark played Valene in "Knots Landing" for thirteen of its fourteen seasons, which made her one of the show's longest running stars.  The character made her last "Knots Landing" appearance in 1997, when she appeared in the reunion miniseries "".  In 2013, Van Ark reprised her character for the new, updated version of "Dallas". Knots Landing is an American prime time television soap opera that aired on CBS from December 27, 1979, to May 13, 1993.  A spin-off of "Dallas", it was set in a fictitious coastal suburb of Los Angeles, and centered on the lives of four married couples living in a cul-de-sac, Seaview Circle.  By the time of its conclusion, "Knots Landing" had become one of the longest-running primetime dramas on U.S. television after "Gunsmoke" and "Bonanza". Paige Matheson is a fictional character from the CBS soap opera "Knots Landing", a long-running serial about middle class life on the fictional cul-de-sac known as Seaview Circle in Los Angeles, California.  She was played by actress Nicollette Sheridan between 1986 and 1993.  She debuted in the penultimate episode of the seventh season and remained in the series until the final episode in 1993.  The character made her last television appearance in 1997, when she appeared in the "Knots Landing" reunion series "". Knots Landing: Back to the Cul-de-Sac is a 1997 American television miniseries.  It is a continuation of the 1979–1993 prime time soap opera "Knots Landing" and takes place four years after the series ended.  Directed by Bill Corcoran, the four-hour miniseries was originally broadcast in two parts on CBS on May 7 and May 9, 1997. Karen MacKenzie (maiden name Cooper; formerly Fairgate) is a long-running fictional character in the CBS primetime soap opera "Knots Landing".  Karen is portrayed by actress Michele Lee, and has appeared on the show since its pilot episode, first broadcast on December 27, 1979.  "Knots Landing" follows the trials of four middle-class families living on a suburban cul-de-sac known as Seaview Circle in California.  Lee portrayed Karen for the entire run of "Knots Landing", being the sole cast member to appear in every episode of its fourteen seasons.  At the time, her appearances in all 344 episodes set a record for an actress on American primetime television.  Karen's storylines focus on family troubles, addiction and kidnapping.  In her early years on the serial, the character had much more of an "edge" in order to test the audience on who would be the most like J. R. Ewing (Larry Hagman), the primary character of its parent series "Dallas".  (The bad girl role would later be taken on by Abby Cunningham, Karen's sister-in-law.) Gregory "Greg" Sumner is a fictional character from the CBS soap opera "Knots Landing", a long-running serial about middle class life on the fictional cul-de-sac known as Seaview Circle in Los Angeles, California.  He was played by actor William Devane between 1983 and 1993.  He debuted in the fourth episode of the fifth season.  Devane remained a principal actor in the series until the final episode.  The character made his last television appearance in 1997, when he appeared in the "Knots Landing" reunion series "". Abby Fairgate (formerly Cunningham, Ewing and Sumner) is a fictional character from the CBS soap opera "Knots Landing", a long-running serial about middle class life on the fictional cul-de-sac known as Seaview Circle in Los Angeles, California.  She was played by actress Donna Mills between 1980 and 1989.  Abby was created by producer David Jacobs as one of "Knots Landing"'s earliest characters.  She debuted in the first episode of the second season.  Mills remained a principal actor in the series until she left in its tenth season.  She returned for the two-part series finale to provide closure for the fans.  The character made her last television appearance in 1997, when she appeared in the "Knots Landing" reunion series "", and was reunited with former cast members. Sweet Revenge is a 1987 American motion picture starring Nancy Allen as Jillian Grey, a newscaster abducted and sold into white slavery while doing an undercover expose.  Ted Shackelford, Martin Landau, Gina Gershon, Michele Little, and Lotis Key round out the cast of this R-rated action adventure directed by Mark Sobel with Roger Corman acting as executive producer. Theodore Tillman "Ted" Shackelford III (born June 23, 1946) is an American actor.  He played Gary Ewing in the CBS television series "Knots Landing" (1979–1993); since 2006, he has appeared in a recurring role on the CBS soap "The Young and the Restless," portraying twin brothers William and Jeffrey Bardwell. Garrison "Gary" Arthur Ewing is a fictional character from the CBS soap opera, "Knots Landing", a spin-off of "Dallas".  The character of Gary Ewing was first played by actor David Ackroyd, in a 2-part "Dallas" episode entitled "Reunion", which broadcast in September 1978.  Gary Ewing was the second son of oil baron Jock Ewing and Miss Ellie Ewing, the father of Lucy Ewing and the ex-husband of Valene Ewing.  Over a year later, the part of Gary Ewing was recast for the spin-off "Knots Landing" with actor Ted Shackelford in the role, and Gary became one of the main stars of the series in December 1979.  Ted Shackelford played Gary Ewing in "Knots Landing" for its entire fourteen seasons (1979–1993), while continuing to make occasional appearances in "Dallas" during that time.  The character of Gary made his last "Knots Landing" appearance in 1997, in the reunion series "".  Shackelford reprised his character for the new, updated version of "Dallas" in 2013.
Answer: Theodore Tillman "Ted" Shackelford III