Two Oscar-winning stars who have acted as the head of the monarchy are taking their talent to the depths of the sea.
Dame Helen Mirren and Olivia Colman have landed new roles as endangered sea turtles in a film aimed at raising awareness of the crisis facing the world's oceans.
The stars, both famous for playing the Queen, voice the parts for Turtle Journey, made by Wallace And Gromit creators Aardman in collaboration with Greenpeace.
The animated short depicts a family of turtles facing oil drilling, plastic pollution and industrial fishing as they try to get home.
Oscar-winner Colman, who stars as Queen Elizabeth II in Netflix's The Crown , is voicing the family's mother
She called the project "heartbreaking".
"Sadly, the story of this turtle family trying to get home in a damaged and changing ocean is a reality for so many marine creatures that are having their habitats destroyed by human activities," Colman said.
"Most of us instinctively love the oceans and care about the amazing marine life that lives there, but far fewer people know how much pressure they are under.
"If we don't act now we risk causing irreversible harm to our oceans and losing species for good."
Colman said home was "the most important thing we have," being a "safe space for us and our family to live".
"But we're taking that away from turtles, whales, penguins and so many other incredible animals," she added.
Dame Mirren, who plays the family's grandmother, won the Best Actress Oscar for her role as Queen Elizabeth II in 2006 film The Queen.
She expressed sadness that her generation would leave future ones a damaged planet "which has already lost so much of the biodiversity that makes it special".
"During my lifetime, I've seen nature being destroyed on an unimaginable scale by human activity," Dame Helen said.
"However, we have a chance to do something now and leave a legacy of properly protected oceans to all the people who come after us.
"We can't bring back what we've already lost, but we can protect what we still have. I hope this film will help to make more people realise the ocean is worth protecting, and inspires us to act before it's too late."
Downton Abbey's Jim Carter, Game Of Thrones star Bella Ramsey, Stranger Things actor David Harbour and comedian Ahir Shah - all Greenpeace ocean ambassadors - also voice roles in the film.
Concerned about a warming planet , Ramsey said the world population and its descendants were watching the actions of governments.
"We, individually, need to play our part, but they, collectively, must act now to create positive, lasting and dramatic change," she said.
Greenpeace UK oceans campaigner Louisa Casson said the world's oceans were in crisis, with six out of seven sea turtle species threatened with extinction.
"Governments have an opportunity to take bold action at the United Nations this year when they meet to agree on a new global ocean treaty," she said.
"A strong treaty would pave the way for a global network of fully protected ocean sanctuaries, placing 30 per cent of the world's oceans off-limits to exploitation by humans and giving marine species such as turtles a chance to recover and thrive."
Turtle Journey ends with a call to action, urging viewers to sign Greenpeace's petition for a global ocean treaty.
According to Greenpeace, ocean warming and changing currents are forcing Pacific leatherback turtles to travel almost twice as far to reach new feeding sites in cooler waters after leaving nesting grounds.
Those findings come from research in French Guiana, where the population of turtle eggs on beaches is around 100 times smaller than they were in the 1990s.
Conservationists say the extra energy turtles use to get to the feeding grounds is likely to be slashing the number of eggs laid each season.
Greenpeace has released the short film as part of its push for a new Global Ocean Treaty at the UN summit and the publication of its report Turtles Under Threat.