Icelandic singer Bjork and her artist boyfriend Matthew Barney have launched their first experimental collaboration at the Venice Film Festival.
Bjork appears in Drawing Restraint 9 and composed its soundtrack
Shot in Nagasaki Bay on a Japanese whaling vessel, Drawing Restraint 9 stars the singer and her partner as human beings who turn into whales.
Bjork also composed the soundtrack for the film - her first since 2000.
"Matthew created the script and the film's universe and I made the music to fit into this universe," she said.
"I had no input into the visuals. If there's any influence it's definitely not conscious."
Bjork vowed never to act again after making Dancer in the Dark in 2000, despite winning a best actress prize at the Cannes Film Festival.
But the singer broke her promise to work with her conceptual artist boyfriend on a film whose "core idea" is described as "the relationship between self-imposed resistance and creativity".
In Drawing Restraint 9, Bjork and Barney first appear dressed in mammal fur costumes.
They then take part in a tea ceremony before blowing through blowhole-like orifices on the back of their necks and cutting away at each other's feet and thighs with knives.
"When we first met we decided not to work together," Bjork said.
"But it came to the point when it was almost easier to work together than not work together.
"We planted seeds for five years without having anything in mind. When we started to do this it was harvest time."
"It was something both of us could sink our teeth into," added Barney.
Drawing Restraint 9 received its world premiere on Friday as part of the festival's Horizons section.