The Duchess of Cambridge has walked the red carpet for the world premiere of a heartfelt film about two friends - a man and his cat - who have transformed each other's lives.
A Street Cat Named Bob dramatises the lives of former homeless busker James Bowen and Bob the cat - familiar characters around central London - who helped each other back on to the road to a better life.
Their story was turned into a book by Bowen and became an international hit, selling more than three million copies, and now a film - starring Bob as himself - is being released about their journey.
Kate, who wore an outfit by Self Portrait, met the pair and members of the cast and crew before the premiere at Curzon Mayfair cinema - in one of London's most exclusive areas.
Waiting at the end of the line of guests were Bowen and Bob, sat on a red cushion on a plinth, and as Kate gently stroked the cat's head she chatted to his owner.
When she bent down to look at the cat, who appeared more interested in the flashes coming from the photographers' camera, she turned to Bowen and asked "is he growling or purring" and he joked that he did not know.
Bowen's story began in 2007 when the recovering drug addict found a stray ginger tomcat injured and sick and curled up in the hallway of his sheltered accommodation in Tottenham, north London.
Bowen was living a hand-to-mouth existence on the streets of London and the last thing he needed was a pet, but he decided to nurse the intelligent tomcat, whom he quickly christened Bob.
The cat followed him everywhere, as he does to this day, sitting on his shoulders with his trademark scarf, and they soon became inseparable.
But Bob, thought to be 11 years old, was also good for his busking in Covent Garden, with the public stopping to stroke the cat, chat and listen to the music.
Taking on the cat was more than just a gesture of compassion, as the former rough sleeper believes it was a turning point in his life.
He said: "He showed me that everybody has a second chance if they want to take it.
"He made me feel, instead of just existing, it was worth changing my life and getting clean because I had to take care of him and in turn it made me take care of myself."
Speaking about the success of his book, which has led to children's spin-offs and now the film, he added: "It's wonderful to be an advocate for things like homelessness charities like the Big Issue Foundation and animal things like the Blue Cross and the Cats Protection League - raising money for all of these things and awareness."
Bowen joked about the happy ending of their tale, saying: "Bob bought a house and lets me pay the mortgage."