Two "Survivor" contestants with ties to Virginia Tech will compete for immunity and the $1 million grand prize when the popular CBS reality series returns in September.

Christiansburg resident Anh-Tuan "Cao Boi" (pronounced cowboy) Bui, who attended Tech, and Adam Gentry, a Tech graduate who lives in California, are part of the latest round of castaways.

Their chance for a million dollars comes seasons after Tom "Big Tom" Buchanan, of Rich Valley in Smyth County, became a popular "Survivor" contestant appearing on "Survivor: Africa" and "Survivor: All-Stars."

While many TV viewers are familiar with the reality series, this season's episodes will center on a new plot twist: the race card.

For "Survivor: Cook Islands," 20 contestants will be organized into four tribes divided along ethnic lines -- black, white, Hispanic and Asian, and the tribes, as usual, will merge later in the season. The 13th edition of "Survivor" will debut at 8 p.m. Sept. 14 on WDBJ (Channel 7).

Bui auditioned with other aspiring survivors on Jan. 31 during a casting call sponsored by WDBJ at Kent Square in Blacksburg.

Bui, 42, was born in Vietnam, where he was a war refugee when he was 11 years old, according to a biography on CBS's Web site and his application video. Later he moved to the U.S. and dropped out of high school to join the military. He attended Tech, and is married to Kristol Bond. The couple have two children, Jesse Dakota and Nicholas Roundtree.

Bui, who considers the character Forrest Gump a hero, has lived a varied life, having worked as a photographer, used car salesman, fisherman and farm hand. He now works as a nail salon manager at Regal Nails in Wal-Mart in Christiansburg.

"He is back," said Vanessa Anderson, who has known Bui for about four years. Speaking on Bui's behalf, she said, "He's not allowed to do any kind of interviews or take any kinds of pictures."

Anderson is administrative assistant/assistant manager at the Montgomery Moose Lodge No. 1470, where Bui serves on the board of officers. "A lot of people know him," said Anderson, adding the lodge is throwing a party for the season premiere of "Survivor." "Here at the lodge he has made a lot of friends. He's not shy; he's outgoing. He's a super nice guy. He would do anything he could for you. He's a crazy, fun, wild guy."

In "Survivor" footage that aired on WDBJ, Bui, who fasts for weeks at a time, said, "The biggest lesson I've learned in my life is perseverance and tolerance. And I think that is one of the keys to world peace and getting along with each other."

According to CBS, Bui enjoys bicycling, hiking, sky diving, photography, meditation and playing classical music on his guitar. He also is the world-record holder in marathon softball where he played for 100 hours while serving in the 82nd Airborne Division of the U.S. Army. In 2003, he hiked the Appalachian Trail, and has biked cross-country.

Bui also is involved with the 82nd Airborne Division Association and the Boy Scouts of America and Cub Scouts of Vietnam.

The other contestant with local ties, Gentry was born in Virginia Beach and later moved to Fredericksburg, according to his biography on CBS.com.

The 28-year-old lives in San Diego, where he sells copiers and aspires to move into medical sales. While at Tech, Gentry, who appeared on MTV's "The Grind," was active in the Sigma Alpha Epsilon fraternity and majored in marketing. After college, he lived in Richmond, where he was a personal trainer for about six months.

As for this season's twist on "Survivor," Jeff Probst, host of the show, said the network was worried the racial divide might offend viewers.

"It's very risky because you're bringing up a topic that is a hot button," Probst told The Associated Press. "There's a history of segregation you can't ignore. It is part of our history.

"For that, it's much safer to say, 'No, let's just stick with things the way they are. Let's don't be the network to rock the boat. Let's not have 'Survivor' try something new," he said. "But the biases from home can't affect you. This is an equal opportunity game."

Probst said he and the "Survivor" producers wanted to bring more ethnic diversity to the competition.

"The truth is 80 percent of the people that apply are white," he said. "And television, in general, is white. So all these criticisms were valid."

On each episode of "Survivor: Cook Islands," at least one cast member will be sent to a separate island miles away from camp, where an immunity idol will be hidden. If found, this immunity idol could save a contestant from being voted off the show.

The Associated Press

contributed to this report.