Quatermass

In an world rapidly unraveling, where violence reigns, and where the law collapses, superpowers unite and attempt to create a united government. But youth populations are attracted by neolithic stone circles where they are harvested. It is a genetic trap planted millions of years ago   by aliens.  Professor Quatermass is once agian there to solve the mystery.

Also released by HBO video in a 2.5 hour movie format in the United States in 1981. This was the last of the Quatermass serials which date back to the 1960's. The best of which was made into the Hammer film Five Million Miles to Earth in the late 1960's...