Director Bryan Singer is currently in post-production on X-Men: Apocalypse, which is set for release on May 27, 2016, but the director seemingly found the time to put the finishing touches on his next project at the same time. The filmmaker celebrates his 50th birthday today, and to commemorate the occasion, he posted a new Instagram photo that reveals his next movie is an adaptation of Jules Verne's classic story 20,000 Leagues Under the Sea. Here's what Bryan Singer had to say in the caption of his Instagram photo, which reveals the title page for his latest script.

"It's my 50th birthday (ouch), and I just put the finishing touches on the script for my next film. A story I've wanted to retell since childhood. I promise this will be an epic and emotional adventure for all ages! An adventure very dear to my heart. Not abandoning the X-Men universe. Very excited about X-Men: Apocalypse and beyond. #julesverne #20000leaguesunderthesea #nemo"
RELATED: Bryan Singer Will Shoot 20,000 Leagues Under the Sea This Fall

20,000 Leagues Under the Sea was originally published as a number of serialized stories between 1869 and 1870, with a deluxe illustrated edition debuting in 1971. The plot centers on Captain Nemo and the crew of his submarine, the Nautilus, as they embark on several undersea adventures. There have been a number of adaptations over the years, including film adaptations in 1916 and perhaps the best known version of 20000 Leagues Under the Sea in 1954, which starred Kirk Douglas and Peter Lorre.

Disney has been developing their own version of this classic story, with their adaptation entitled 20,000 Leagues Under the Sea: Captain Nemo. David Fincher was attached to direct for some time, but he ended up bowing out in favor of making Gone Girl. We reported last August that Disney was planning on starting principal photography sometime this year, but we haven't heard anything about that project since then. It is believed, but not confirmed, that this version of 20000 Leagues Under the Sea is being set up at 20th Century Fox.

No details have been given for Bryan Singer's version of 20,000 Leagues Under the Sea, and it isn't known when he may start production. The director doesn't officially have any other projects in the works, but there have been rumors that he is developing a crossover between the X-Men and Fantastic Four. While we wait for more details on 20,000 Leagues Under the Sea, check out the script cover photo, which reveals that Bryan Singer worked on the script with Rick Sordelet and Dan Studney (Jack the Giant Slayer).