Northern Limit Line

Director Kim Hak-soon acquired the rights of the same-named novel by Choi Soon-jo in 2006 and planned to film the movie in 2007. But the families of the soldiers who had died in the battle had been against the movie, so Kim stopped the Project back then. But after the sinking of the war-ship Cheonan in 2010, the families made contact with Kim Hak-soon and asked him to do the movie.

ER doctors shocking a flat line cardiac condition (twice) and getting a heart beat reestablished (once). The shock is done to stop the heart beating in an irregular rhythm which then allows the intrinsic pacemaker to take over and produce a regular rhythm. In other words, shocking the heart produces a flat line which allows a regular rhythm to take over. Shocking a flat line is not done because there is no rhythm to reset; it only produces a continuing flat line. AEDs are programmed not to shock a flat line and it is not done manually either.