The Fathom comic book, created by the late Michael Turner, follows the story of Aspen, a member of an aquatic race of humans called the Blue, discovering her heritage and the power to control water after being raised by normal, land-based human beings. Mechner is penning the script, making this his second stab at screen writing a major feature film, with the upcoming live-action Prince of Persia film being his first, along with a couple of documentary credits. It should be relatively easy for him though, seeing as he has a wealth of comic book material to draw reference from.
Perhaps even more exciting that Mechner's writing is the fact that Transformers co-star Megan Fox has been tagged to play Aspen. I don't normally rawr, but in this case...rawr.
Megan Fox looking at Fathom, Jonah Hex [The Hollywood Reporter]