Children are being given the chance to party alongside stars including JK Rowling at the Queen's star-studded 80th birthday bash in June.
A lottery will be held for UK children between the ages of four and 14. Kids picked at random will go to Buckingham Palace for the special tea party.
The theme is British children's stories so characters like Tracy Beaker and Paddington Bear will also be there.
Anyone interested can apply via the CBBC website up until 28 February.
Who'll be there?
Mowgli from the Jungle Book
Winnie the Pooh
There was such a demand for tickets in the first two hours that the CBBC web page where you can apply crashed, although it's back up and running now.
On being invited to the bash JK Rowling told CBBC: "I can think of no better way to mark the Queen's 80th birthday than with a party for children at the Palace with some of the best loved characters from children's literature.
"Harry and I are very much looking forward to attending, particularly as we understand that, despite his alleged membership of the aristocracy, Lord Voldemort has not been invited."
Author and Children's Laureate Jacqueline Wilson, who'll also be at the party said it was going to be a "very exciting event":
"There's going to be all different characters from favourite children's books, there's going to be a magnificent play, heaps and heaps of different things for children to do.
"I can't wait until June to enjoy it myself!"
The big show
Lots of stars are expected to attend the party and will perform in a massive show in the evening that will be shown live on BBC TV.
A spokesperson from the Palace said: "The Children's Party at the Palace will be a celebration of British children's literature, both traditional and modern, which we hope will encourage children to read and enjoy books."