Zak McKracken and the Alien Mindbenders

Zak McKracken is a tabloid reporter (and not a very good one at that). After having a psychedelic dream one day, Zak realizes that something is wrong -- space aliens are dumbifying the general public through the telephone system. Zak must stop this, but he can't do it alone. After finding a strange crystal, Zak manages to get the help of the anthropologist Annie and her friends, Melissa and Leslie. The four unlikely heroes must now figure out a way to destroy the dumbifying devices and save the Earth.