JK Rowling has sparked excitement among Harry Potter fans by posting a cryptic tweet.
The author informed her millions of followers that she was "very busy" at work on a novel, a screenplay and campaigns for her children's charity Lumos.
One fan, Regan, replied saying that everytime Rowling tweets she has to "stop whatever [she is] doing and analyse it for an hour".
Roughly 14 hours later, Rowling responded to Regan admitting that she was "tempted to post a riddle or an anagram" but should "resist temptation and work".