Over in minutes, the "Shakespeare pop-up" is one of a series taking place on London's streets this week, as actors ambush the public, giving personalised one-to-one performances of some of the Bard's most famous passages to mark the start of the Paralympic Games on Wednesday.
Classic characters such as Puck, Hamlet, Cleopatra and Juliet, along with more modern flashmob stunts, will be played by a cast of 50 performers that includes deaf and disabled actors.
"A lot of the actors we're using are not actors, unfortunately, that you will see at the Globe or the Royal Shakespeare Company," said actor Mark Rylance, who created the event.
"They have a much more unique and individual approach with the stuff," he said, describing the performance of Hamlet's "to be or not to be" soliloquy by one actor with Down's Syndrome as "phenomenal".
"Talking from memory, because of his syndrome, it takes an enormous amount of concentration for him to speak the words, so it appears that he is digging it from so deep inside to share it with you," Rylance said.
Shakespeare, Britain's greatest cultural export, featured prominently in the opening and closing ceremonies of the London Olympic Games and the city has now shifted its focus to the Paralympics.
"We've certainly tried to mirror (the Paralympics) in the range of abilities of people involved," said actor Jonathan Moore, who directed the performances for the London 2012 Festival.
"I think it's completely congruent with Shakespeare's all-embracing humanity, the fact that he can speak to everybody not just in terms of different cultures, in terms of different intellectual ability, but in terms of every ability," Moore said.
A record 2.4 million tickets have already been sold for the London Paralympics, overtaking the previous record set four years ago in Beijing by 600,000.
The success of Britain's Olympic athletes, who won the most gold medals of any British team since 1908, is thought to have boosted ticket sales.
To qualify, Kelly has had to shift from racing the 100 breaststroke - an endurance event in Paralympic terms - to sprinting in the 50 distance.
While mastering the new discipline and training hard in his other events, Kelly has had to juggle school work while supporting his mother's charity, the Children First Foundation.
"It has been difficult, but you have to do your best," Kelly told Reuters. "It's tough, but it's meant to be tough ... You have to know what you're doing every lap for."
Kelly and his coach Harris remain as ambitious as ever.
"I love sports, I want to keep swimming well, keep adapting, and I'm still learning about these things," said Kelly, who has already set his heart on competing at the 2016 Paralympics in Rio.
"I want to get the best out of myself. But everyone has been so supportive and I couldn't have done it without them."
- Royal Shakespeare Company