By Piya Sinha-Roy LOS ANGELES (Reuters) – “Harry Potter” fans received fantastic news on Thursday. Author JK Rowling said the Potter spin-off film series “Fantastic Beasts” will consist of five films, instead of the previously announced three. “We set a trilogy as a placeholder because we knew there would be more than one film, but … we’re pretty sure it will be five films,” Rowling told attendees at a fan event in London. The British author of the bestselling “Harry Potter” books was a surprise person at a question-and-answer event with the cast of “Fantastic Beasts” in London and Los Angeles that was broadcast worldwide. The news was greeted with excited cries from the audience, while the cast, including Oscar winner Eddie Redmayne, appeared surprised when they first heard the news. The films will be released by Warner Bros, a subsidiary of Time Warner Inc. A 4-minute Fantastic Beasts featurette shown at Thursday’s event finally gave a hint at the rest of the film’s plot, which has been kept secret until now. The planned films, designed as prequels to the Potter stories, will trace the rise of a powerful wizard named Gellert Grindelwald and his eventual duel in 1945 with Albus Dumbledore, the beloved wizarding headmaster from the Potter stories. “We’re talking about the first time a wizard rose and threatened the world order. That’s always been my interest. That’s what I wanted to do,” Rowling said in the featurette. She added in the 4-minute video that the new films will be tied to the Potter stories in “surprising” ways. Fans at the event were shown the first 10 minutes of Fantastic Beasts, which hits theaters on Nov. 18. The film follows Redmayne’s “magizoologist” Newt Scamander, who arrives in New York City in 1926 with a suitcase full of magical creatures, amid growing unrest in the wizarding world. When Scamander’s creatures escape and cause chaos, it poses an even greater threat to the magical community, as they could be discovered by the city’s non-magical people. Fantastic Beasts follows the eight-film Potter series, which officially ended in 2011 with Harry Potter and the Deathly Hallows: Part 2. That series grossed over $7 billion at the box office worldwide. Rowling’s seven-book series has sold over 450 million copies worldwide. Earlier this year, a sold-out London play, Harry Potter and the Cursed Child, rekindled the magic, and the book version of the screenplay became a best-seller. (Edited by Jill Serjeant and Matthew Lewis)