The aliens' objectives are not explained until season 4. They plan to extract helium-3 from Earth's moon to power their technology, and to use humanity as an enslaved front-line army in their war with another alien race. To do this, the aliens round up children between the ages of 8 and 18 and attach a biomechanical mind control harness to their spines. Forcibly removing it generally kills the child, but midway through season 1, a surgical method is developed that allows a harness to be safely removed, leaving in place the "spikes" that connected the harness to the spinal column. In Season 5, it is revealed through an Espheni communication device—which Ben can interact with by touching it, due to having the spikes—that there is a being superior to the Overlords, known as "the Queen". In the series finale, the Queen explains that the invasion upon which the entire series is based is the result of a prior Espheni attempt to invade Earth, the only habitable planet in this galaxy and thus of immeasurable strategic importance. Her beloved daughter led that invasion, but the Espheni underestimated humanity and the invasion was stopped. The Queen's daughter was killed and the Queen swore to wipe out humanity in revenge.
The Wizard of Oz
# 234 on IMDb Top Rated Movies
Falling Skies is an American post-apocalyptic science fiction television series created by Robert Rodat and executive produced by Steven Spielberg . The series stars Noah Wyle as Tom Mason , a former history professor who becomes the second-in-command of the 2nd Massachusetts Militia Regiment, a group of civilians and fighters fleeing Boston following an alien invasion that devastated the planet.