First Wave is a Canadian science fiction drama television series, filmed in Vancouver, that aired from 1998 to 2001 on the Space Channel in Canada. The show was created and written by American screenwriter Chris Brancato. Francis Ford Coppola was executive producer on the show. In an unusual move, the Sci-Fi Channel, which picked up the show in late 1998, later expanded their pickup of the series to a 66-episode order. The show was subsequently cancelled once the 66-episode order was filled at the end of the third season due to disappointing ratings.

Former thief turned security specialist Kincaid Lawrence "Cade" Foster's life was idyllic, with a beautiful wife, good job and a nice house. Unbeknownst to him, a race of extraterrestrials called the Gua have identified him as subject 117 in an Alien experiment - AHX2323 - to test human will. As part of this experiment, his life is systematically ruined, including the murder of his wife, for which he is framed. He is the only one of the 117 subjects to solve the riddles of the experiment and escape arrest to live as a fugitive. The Gua are among humans in the form of hybridised genetic clones and plan to enslave humanity—the first of three "waves" intent on conquering and finally destroying the human race. Constantly pursued by the police, and a strange government agency called the Illuminati, Foster discovers previously unknown quatrains of Nostradamus, which tell of three waves that will destroy the planet unless the "twice-blessed man" can stop them. For this reason, Foster investigates strange occurrences that may have ties to the Nostradamus quatrains, hoping to find what he needs to stop the Gua.

"Crazy" Eddie Nambulous is a computer hacker who helps Cade Foster and works on a web tabloid Paranoid Times. He uses Cade's journal to tell people that the "aliens are here, walking among us, laying the groundwork for an impending invasion." After scanning the prophecies of Nostradamus into his computer, he analyzes and cross-references the quatrains with bizarre current events to which they may be connected. Foster and Eddie use these quatrains to understand the Gua invasion and search for any and all tools that may aid them in stopping the invasion in its First Wave.

One of the Gua, Joshua, does not believe the invasion of Earth is necessary. Although he wants the best for his people, he helps Cade and Eddie stop his people from initiating the "Second Wave" — the invasion itself, in which 19 million people will die.

We were like you once. There's a time for peace and inner-growth, but we became complacent; and when the invasion force landed, they took us down. One rebel led us to freedom. That's when we took the name Gua; it means "power to overcome". Over the centuries, science and industry achieved perfect focus. We created a military machine to ensure our freedom, permanently... We're here because we'll never be victims again."

The Gua are a race older than humanity, coming from a much older star system. As Joshua tells Cade, "Everything on my planet is red, the colour of a tired sun; the colour of death" which indicates that their home system is at a much later stage than our own, and that their sun is entering a late phase of its life. The Gua originally existed peacefully, exploring their inner selves until they were invaded and enslaved. Eventually, they rose up and overthrew their oppressors, taking the name Gua from that climactic, defining event; Gua meaning "power to overcome".

As a consequence of this invasion, the newly named Gua decided they could no longer afford to be passive and peaceful, and set out on an aggressive, expansionist path. Aware of the limited lifespan of their home planet, they began a campaign to expand into other systems. Thus their invasion of Earth was planned.

Due to the distance between Earth and their own planet, the Gua devised a method of dispatching small metallic orbs containing their consciousnesses through wormholes to Earth and transferring them into specially bioengineered human husks. As a result of this, it is unknown what the Gua actually look like.