The 90's weren't kind to genre shows with quick cancellations of Nowhere Man, Harsh Realm, the Dark Shadows remake, and American Gothic. In the noughties, well thought of series such as Journeyman, Surface, Invasion, Persons Unknown, Flash Forward, Firefly and others, didn't fare much better and were all gone within a season. Threshold is another show that was given little chance of success, despite its potential, and was gone in 13 episodes.
The Threshold series comes from the post X-Files world, where everyone knows that aliens and conspiracies run rampant on planet earth, but the government does their best to convince us otherwise. The story starts when a naval ship ( the humorously named USS Bighorn ) sights a UFO and most of the crew are killed. The government enacts the Threshold Protocol led by Dr Molly Caffrey ( the convincingly smart, realistically unsettled, and cute in glasses, Carla Gugino from Watchmen ), and including Data from Star Trek The Next Generation, Charles S Dutton ( Alien 3 and Mimic ) and the midget from Death at a Funeral.
Caffrey discovers that aliens are trying to rewrite human DNA with audio signals ( something I believe has also been tried at recent music festivals, judging by some of the "people" I often find myself traveling with on public transport ) and some sort of cosmic Spirograph. If the aliens were a little trendier, and had some level of forethought, they could have planted their signal in iPods, and changed the world quicker than even Steve Jobs or Mark Zuckerberg might have imagined.
The writers were careful to not reveal too much too quickly, but failed to reveal enough to capture the audience they needed. Mix together "Invaders", "X-files", and the "Thing" and you've got an idea of what to expect. Sure, they're here, but 5 years on, do we really care?