Series
- Cult Classic: Came out with the crowd of the post-Lost "mystery box" series and due to reasons, picked up a very strong following among the handful of people that knew it existed. It's one of the few TV shows from that era that maintains any sort of following to this day.
- Designated Hero: Cavanaugh. In the pilot alone, he bugs the homes of his fellow team-members without permission, has the team implanted with tracking devices, routinely roughs up anyone who questions why he is violating their civil liberties, and uses his firearm as both a lockpick and television remote.
- Fridge Logic: What exactly was the threat of the North Koreans in the pilot? The US team was already on the scene and securing the vessel? Not to mentioned the reason to destroy the vessel was to stop it falling into their hands? How? It was a US vessel, with US military personnel onboard... to do so would have been an unprovoked act of war.
- For that matter, what in the name of Kim Il-Sung was a North Korean submarine doing in the North Atlantic?
- And they explicitly said it was a Kilo-class sub. An American Los Angeles class would consider a Kilo target practice.
- Harsher in Hindsight: In the pilot, Caffrey's contingency planning speech includes her saying the world needs to prepare for a global pandemic of a SARS-like virus. Turns out she was right.
- Hilarious in Hindsight: Carla Gugino would go on to play a UFO researcher in Race to Witch Mountain, which also stars Ciaran Hinds as a MIB-type character akin to Dr. Caffrey.
- Nightmare Fuel: A zombified child speaking taunts from the Big Bad to his dead father? More than a little creepy!
- Retroactive Recognition: It's Tyrion Lannister as a Cunning Linguist!
- Even more amusingly, Ramsey and Tyrion are both similar in personalities, especially in their favorite pastimes.
- It seems that Chuck Shurley is apparently an aerospace engineer in his spare time away from being, you know, God.
- So apparently Ted Sprague lived in the 19th century and fought aliens... cool.
- Too Good to Last: Good cast, solid writing and performances, avoidance of all the pitfalls of its contemporaries... and cancelled while still on air, after continous meddling to not air the show in the first place.
- Whole-Plot Reference: The War on Terror with alien invasion! All the shady moves Threshold does, especially the indefinite detention without court or any information, are portrayed with their full moral ambiguity.
Novel
- Complete Monster: Nzame is an Eldritch Abomination from beyond our world. Finding a way into our world, he turns the portal into an Eldritch Location and murders several people working on this portal in increasingly horrific ways. He uses this portal in the form of a pyramid to breach into the human world and mind rapes the population of Threshold into worshiping him. Once they do, he transforms them into stone golems in constant pain. When the protagonists rise to oppose him, he attacks them through their dreams, threatening bodily harm to them and their loved ones. He pays special focus to the heroine, Tirzah, threatening to possess her unborn child and leave her husband trapped in an Eldritch Location. Twisted and cruel, Nzame does not care for anything but himself and power.
