Guy Williams as Diego de la Vega

Bonanza fans had better take a close look at the Ponderosa. Soon it won't be the same. A blond and Zorro himself are moving in. The blond is Kathie Browne.

Zorro, of course, is Guy Williams, best known for his title-starring role in Walt Disney's "Mark of Zorro" series.

As the sword-wielding Zorro, Williams was the Robin Hood of Old California. But he has long abandoned that role, and this time will be seen in Western garb befitting a Ponderosa resident.

Williams becomes a regular as a hedge against the day Roberts leaves and also to ease the work load of the other stars, Lorne Greene, Dan Blocker and Michael Landon.

Kathie is slated to make her debut in an episode called "The Waiting Game." Present plans call for NBC to show it on Dec. 8.

No air date is set for Williams' introduction to the series, although he is scheduled to start filming a two-part story on Nov. 11. He will portray Will Cartwright, a younger brother of Ben Cartwright (Greene), the silver-haired patriarch of the vast Ponderosa.

While the storyline being developed calls for Kathie to marry Roberts, David Dortort, the executive producer, said he will play it pretty much according to viewer reaction. If it's strongly against romance on the Ponderosa, there probably will be no marriage.

For Kathie, her role of a young widow in "Bonanza", no matter how short-lived it may turn out to be, is her chance of a lifetime.

She goes from near-obscurity to what has been NBC's most popular show.

The green-eyed actress is determined to become a permanent fixture in the series, regardless of what the script writers may have in mind.

Lorne Greene as Ben Cartwright

"The women will want me," she said. "They like a little romance with their television shows. Some men may resent me, but most of them would rather see more girls and fewer horses on the show." Roberts has long been wanting to get out of the series and into something "with a greater social conscience, something more vital and meaningful," as he has often phrased it in interviews.

There is a possibility that Kathie may become so popular with viewers that Dortort will want to keep her in the series. That would create a problem trying to keep her around if Roberts leaves.

She could, of course, become a widow again. Ben Cartwright has well established that precedence. He's a widower three times over.

This will be Kathie's first major role in television. The native of San Luis Obispo, Calfi., has been doing relatively minor roles in various television series for the last three years. She faces one big problem in joining "Bonanza". Kathie's afraid of horses. "But a girl who looks a lot like me is doubling for me in all the riding scenes," she said.

Kathie should have little trouble acquiring the proper attitude for a husband-hunting girl in "Bonanza."

"I'm unmarried myself in real life," she explains tartly.

How will romance and a new brother work for Ben Cartwright? Lorne Greene smiled. "I have no problems that can't be solved in an hour," he said. "Everything's under control on the Ponderosa."

Pernell Roberts  Kathie Browne

The Detroit News TV Magazine.