The Laser Beam Sword was developed in the early 21th century when they first started developing portable destructive laser beam technology linked to a very original Sci-Fi contest sponsored by Gamebanana where it won the 1st Place!
Some time later a big accident happened in the factory, releasing a dangerous virus that turned almost everyone immediately into brainless zombies roaming the earth.
However there were some uninfected by this virus and who would wield this most dangerous sword to defeat the virus itself and everyone who crosses their path!
You can download it over at Gamebanana as a playable skin for Left 4 Dead 2!