the arctic some kind a unknown virus appear deep down ice. research team is gone like in the movie thing or x-files serie...Put all files in to map folder left4dead map directory.use console for map start. type console "map l4d_sv_arctic" for enter.this is my first ld map and not a finished version if anyone want to finish enjoy.i have a problem with nav editing back then... just want to add to my nexus.