Espheni

The Slenders is a name given by fans to the yet unamed alien overlords in the series Falling Skies.

Appearance
The Slenders are tall, thin, bipedal grey aliens. They tower over humans and Skitters.

In the Series
Revealed near the end of the series the Slenders are the apprent masterminds behind the invasion of Earth in Falling Skies. They are first seen in Episode 8 by Tom Mason, Hal Mason and Captain Dan Weaver on a scouting mission in the city. Tom believes that the aliens are only now showing themselves because they believe they are safe and have won.

It is also learnt through examination of a Skitter corpse that the Skitters are also slaves due to the discovery of a harness burried in the corpse's spine. The resistance concludes that the Slenders use the Harness to generate the Skitters as a form of slave labour and then shock troops once the victim has been transformed.

In the series finale the Resistance is able to launch a powerful counterattack against the invaders. After discovering the Skitters and Mechs are linked through a radio frequency they come up with a jamming frequency that they use to disorientate and repel an attack on the Resistance base. This leads to a mass retreat by the alien forces back to the structure in the city. Resistance fighter Tom believes that they have managed to confuse and possibly even scare the aliens. Taking advantage of the retreat Tom is able to fire a missile at a fleeing ship that crashes into the Alien structure causing signifigant damage.

As Tom and Weaver are returning to the Resistance meeting point they are confronted by former comrade Karen; who has been harnessed weeks ago. Approaching her cautiously Karen adressess Tom and says that the Slenders brought her here because they don't understand. An Alien ship with a Slender arrives and Karen explains that the Slenders did not anticipate such resistance from a less advanced race than their own. This has interested them and they now want to talk. Weaver and Tom are furious at this revelation that the aliens are only now acknowledging their victims when they fight back hard.

It is soon revealed that the aliens want speifically to speak with Tom since his son is still under the influence of the Harness conversion prosess, due to it being removed too late. In exchange for going with the aliens Tom's son would be released from the prosess; with no other option Tom is forced to leave with the aliens ending the first series.

Purpose
Has of yet the aliens motive behind the unprovoked invasion has yet to be revealed.