Vin Diesel bursts into a quiet hotel room, his team in tow, brandishing a speaker attached to his mobile phone.
The Hollywood action man then selects a disco track to blast out (the 1974 Redbone tune Come And Get Your Love) and proceeds to shake his gym-honed body to the beat, as an assistant films proceedings for the star's "archive".
It's not exactly the entrance you'd expect from the Hollywood tough guy, known for portraying gravelly-voiced, burly bruisers in films such as xXx and the Fast & Furious franchise.
But then, Diesel's latest acting gig couldn't be further removed from the usual 'hard man' roles, which have helped earn his Facebook page almost 82 million 'Likes'.
The 47-year-old former bouncer provides the voice for a giant tree creature named Groot in the Marvel action movie Guardians Of The Galaxy (which features the Redbone song on its soundtrack).
Groot and his fellow Guardians, a quintet of intergalactic misfits led by adventurer Peter Quill (Parks And Recreation star Chris Pratt), must ensure that a potentially destructive orb doesn't get into the hands of a power-hungry villain called Ronan.
Loyal, kind and mighty, Diesel's character takes the notion of a strong, silent type to the extreme - he can only communicate using three words ("I Am Groot") and a series of grunts.
"It's the most innocent character I've ever played, clearly, which is why I've kind of been so silly," Diesel says when he settles down post-dancing, his sizeable muscles packed into a dark T-shirt and combats.
"I'm not talking about heavy issues that I'm usually talking about with the movies I make... I get to have fun!"
It's been a difficult few months for the New York-born actor, whose friend and Fast & Furious co-star, Paul Walker, was killed in a car crash during a break from shooting the hit franchise's seventh film last November.
A hush descends on the room as Diesel discusses finishing the film without his friend, whose brothers were drafted in to help complete his unfinished scenes.
"[It] was the hardest film to do - and blessed, because there was such a sense of family and coming back. But surreal," he says, looking downwards as he speaks.
"You would never imagine that you would ever have to mourn someone so close to you, and simultaneously pretend that they're sitting next to you. It's kind of a strange thing to have to do as an artist, and as a human."
Voicing the role of Groot shortly after the tragedy was a "very healthy and therapeutic thing to do" for the actor.
"When we deal with death, our appreciation for life is represented in so many ways," he adds. "We appreciate everything that's alive, the very trees in our backyard. And this character [Groot] celebrates life, in so many ways."
Diesel, who has two children with his model girlfriend Paloma Jimenez, says it was his three-year-old son who encouraged him to play Groot.
"I remember someone in my office saying, 'No, you've got to play this or that, what the hell are you going to play a tree for?'
"I went to the living room and showed my children the concept art and opened it up to a page where it had all the characters and said, 'Which character do you think Marvel wants Daddy to play?', and my son pointed to the tree."
He continues: "Jump cut to him seeing the movie with me... As I was riding home, my son was looking out the window at trees and he said, 'Daddy, look, it's your brothers and sisters'."
Director and co-writer James Gunn supplied Diesel with a special script for his stints in the voice-over booth.
"With every 'I Am Groot', on the right hand side of the page was a paragraph or a sentence of what Groot was really saying," the actor explains. "So that was how I was trying to get the meaning into each 'I Am Groot', and make each of them different."
Diesel, whose breakthrough role came in the 2000 sci-fi thriller Pitch Black, and who has also worked as a producer, director and screenwriter, insists that voicing a monosyllabic tree alien wasn't easy.
"I was being challenged as an actor, as a thespian - the idea of playing a character without any facial mannerisms or allowing your body physicality to play into the character, and being limited to such a small vocabulary," he says.
Despite never appearing on screen, Diesel wanted to understand Groot's movements, and so donned a pair of jumping stilts.
"[I wanted] to feel a little bit how it would be to be this towering figure. It played into the character and somehow affected my performance," he explains.
Getting the moves right is important for the star, who was part of the breakdancing scene in Eighties New York (in fact, some of his early performances can be found on YouTube).
Before Hollywood came calling, Diesel made ends meet as a bouncer - "because I could dance for free in nightclubs".
"The only time I got in trouble, as a bouncer, was when I was dancing," Diesel adds with a smile. "Watching my children dance has changed my whole perception of dance. I appreciate the - what would you call it - non-dance dance. My kids move with no rhyme or reason and there's something so fascinating about that."
Fittingly, Groot gets to display some dance moves of his own in a sweet scene during the film.
As Diesel's 'people' try and hurry him along to his next engagement, the star grandly announces: "I am going to let you be Groot. This is an exercise and you don't have to participate if you don't want to, no one will judge you..."
He proceeds to pick up his phone again and urge those present to start shaking their shoulders, whooping and cheering his encouragement as an upbeat song plays out.
"That felt good and you know it! You feel liberated, you feel like a better person.
"At the end of the day," he adds, his voice becoming a deep growl: "We. Are. Groot."
And with that, the breakdancing, stilt-wearing, tree-hugging action man makes his exit.
EXTRA TIME - MEET THE GUARDIANS OF THE GALAXY :: Peter Quill (Chris Pratt) - Quill is an interstellar adventurer who was abducted from Earth at a young age. His late mother gave him a Walkman full of retro hits, which he dances to at every opportunity.
:: Gamora (Zoe Saldana) - Green alien Gamora was abducted and raised by mysterious ruler Thanos to become his personal assassin. She now wants redemption for her past crimes.
:: Drax (Dave Bautista) - Muscle man Drax wants revenge against villainous Ronan, who killed his family. With his penchant for big words, he's been described as a walking thesaurus.
:: Rocket (voiced by Bradley Cooper) - This bounty hunter and mercenary is a formidable warrior - despite being a cybernetically enhanced, talking raccoon.
:: Groot (voiced by Vin Diesel) - Groot descends from a race of walking flora and resembles a living tree. What he lacks in communication skills, Groot makes up for in loyalty and strength.
:: Guardians Of The Galaxy is released in cinemas on Thursday, July 31