Author JK Rowling has said she felt euphoric but "devastated" as she penned the last words of the final Harry Potter book, The Deathly Hallows.
Speaking on Jonathan Ross' chat show, she said: "When I finished one chapter near the end I absolutely howled."
She also revealed the character of Harry was "totally imaginary" and not based on anyone else, while Ron Weasley was a lot like her oldest friend Sean.
The interview will be broadcast on BBC One on Friday night.
She was in a hotel room alone as she finished writing the book.
"I was sobbing my heart out, I downed half a bottle of champagne from the mini bar in one and went home with mascara all over my face, that was really tough," she said.
When asked about whether "scar" was the last word in the book as had been reported, she said: "Scar? It was so for ages, and now it's not. Scar is quite near the end, but it's not the last word."
She also said it had been a "a hell of an achievement" to keep the cast of all the Potter films British.
Nearly 1.6 million copies of the final Harry Potter book have been pre-ordered online ahead of its release on 21 July.
The latest film in the series, The Order of the Phoenix, had its European premiere in London on Tuesday.
The film opens worldwide from 11 July.