Siska hanging tough in 'Survivor'

It took a cool head -- and some powerful lungs -- for Jason Siska of Fox River Grove to best nine other contestants in a "Survivor: Micronesia" challenge. He managed to keep his head under a metal grate the longest as the water level rose and rose, forcing the other contestants to give up and gasp for air.

That won Siska, 22, immunity for the night. He was the only one to get it, since the two tribes merged in this show and formed a new tribe, the Dabu. Despite his proven ability to win challenges, Siska still worries he's targeted.

He and Eliza formed an alliance, and he gave her an idol he'd found on Exile Island, which he thought was an immunity idol. Eliza thought it looked fake, but played it because she suspected she was going to be ousted.

Host Jeff Probst announced it was indeed fake, and she got voted off. She will become the first member of a jury that will weigh in during future shows. That leaves Siska without an ally.

And he's engaging in rivalry with Ozzy, a powerful person to cross. They were the last two to stick it out in the challenge, and Siska got the satisfaction of winning when Ozzy had to come up for air. But Ozzy, who had earlier planted the fake immunity idol, got the last laugh when Siska, and his ally Eliza, fell for that trick.