Invisible Laser Zombies From Space

Space Zombies have infested our strangely roofless yet dazzlingly shiny portal facility. Your job is to kill them. Weve equipped you with a top of the line laser gun that will slice straight through them, and make a neat little sound while its at it. Theres just one small problem: The zombies are invisible. Sometimes they leak a bit, but theyre mostly invisible. Whats that? You got that bit from the title? Ok, have another problem: The shiny walls of the facility are made of magic, and as such will reflect any stray laser shots straight back at you, no matter what angle you fire at them. So tr...