How do you keep it a secret that the Duke and Duchess are coming to visit your school? You don't tell the 1,050 students who attend Macarthur Girls High School in Parramatta.
Only the head teacher, her deputy and the groundsman were supposed to know what was going on. In fact, it was only yesterday they were told that someone from parliament would be visiting today.
But the word, thanks to social media, got out.
Premier Gladys Berejiklian was the warm up act. Addressing a special outdoor assembly she asked: "Have you ever had so many helicopters over your school?
"Most of you would probably have got up this morning, got ready for school and turned up thinking it was going to be a normal day at Macarthur Girls School. Is that right?"
The answer was unanimously "No."
The premier added: "You knew I was coming. Did you know anyone else was coming?"
The whole school erupted in shrieks and cheers as Prince Harry and Duchess Meghan walked into the assembly.
Meghan wore a stunning Roksanda navy dress with a light blue trim and high heeled beige shoes.
As they sat down, they first saw a display of dancing, appropriately named for the newlyweds 'The Power of Love'.
WATCH: Prince Harry and Duchess Meghan watch a dance performance at Macarthur Girls High school:
Next it was to the library where the royal couple learnt about a Year Nine project where they are investigating issues of social justice, including women and youth empowerment.
"We are investigating how young people can make a difference," one student explained.
She added to laughter from the royal couple: "It's about dignity, quality, freedom [she hesitated for a second] and there's a few others as well."
When other pupils, overwhelmed by meeting the royals, struggled to remember their words, the premier was quick to help out.
And then it was over. It was only 30 minutes, but the girls were blown away.
Maithly, 15, said: "It was a lovely experience and beyond anything I would have ever expected.
Nirel, also 15, said: "I was speechless. She, Meghan, is absolutely beautiful. Prince Harry is absolutely beautiful too."
Rhiannon, 15, couldn't contain her excitement. "When they walked in I felt like my heart stopped," she said.
"Their presence just made everyone shocked. I never thought this would actually happen at our school."