Isla Fisher thought she was going to die when filming 'Now You See Me'.

The 37-year-old actress plays an escapologist in the Louis Leterrier-directed movie and admits she ''panicked'' during scenes where she was fully submerged in an underwater tank, so she was relieved when her hard work paid off.

She said: ''There were a few dodgy moments where I panicked that I couldn't get out of the tank. I'd think, 'So this is how I go. Didn't see that one coming!' ''

''It felt great when the director said to me, 'You know, I've had actors before who wouldn't feel comfortable doing the stunts that you felt comfortable doing.' ''

Isla - who has children Olive, five, and Elula, two, with husband Sacha Baron Cohen - relies on ''gut instinct'' when it comes to accepting work, and looks for roles which are ''interesting''.

Asked how she picks her parts, she explained to Britain's HELLO! magazine: ''Gut instinct. If something really terrifies me and I think I'm going to ruin it, then I'm going to do it. Like 'Now You See Me', where I'm playing this sexy magician who swims with piranhas. I'm like, why would I be offered that role?

''I don't see myself as particularly brave or sultry, which is what was called for. So I took the job because it's interesting.''