Hayden Christensen, Rachel Bilson and Doug Liman on the set of 'JUMPER'

The 28-year-old beauty truly suffered for her art appearing alongside her reported boyfriend Hayden Christensen in the sci-fi film, as she had to face her nightmare head on.

She says, "Hayden and I are both submerged, fully dressed, in supposedly icy water in a river in Michigan.

"For me, having to be underwater with oxygen was very difficult and uncomfortable. I can swim, but I have a real fear of drowning. It was the scariest thing I've ever done."

Source: WENN