It's been nearly four years since Michael Mann last directed a feature film, but the wait for his next project may be over: The " Public Enemies " director has attached himself to helm an untitled thriller for Legendary Pictures with Chris Hemsworth attached to star. Mann had been developing the project for over a year, co-writing the script with Morgan Davis Foehl, who is also penning "Mass Effect" for Legendary. Plot details are unknown, other than that the film takes place in a world of cyber threats and attacks. Thomas Tull, Mann and Jon Jashni will produce with Alex Garcia exec producing. Mann had most recently produced "Witness" and directed the pilot of HBO's "Luck," which he also exec produced but has not helmed a film since Universal's "Public Enemies" in 2009. Mann has since been linked to a handful of films, including "Big Tuna, "Agincourt" and the racing pic "Go Like Hell" fo