The Invaders Season 2 Ep 7 - The Spores torrent

Courier Tom Jessup loses track of a briefcase containing something vital: spores. These organisms, properly nourished, will grow into aliens able to tolerate Earth's high oxygen content. Through mischance, Jessup loses track of the briefcase, which changes hands several times. Finally, some kids wind up with it, and meanwhile inside it the spores continue to grow, and outside it, Jessup is increasingly desperate