In a rundown motel, Lieutenant Martin Kirn (Sal Landi) meets with a reporter to tell what happened on his final military mission.

Since at least World War II, the United States government has successfully covered up very real proof of U.F.O.s. However, when a group of U.S. Marines is dispatched to a deserted island to defuse an old ordinance. The military task force is not made-up of elite military units.

Kim learns that Captain Fetterman (Andrew Divoff) chose the soldiers for the mission as they are expendable. Despite their inadequacies, they soon suspect something is amiss about the mission. They uncover unsettling evidence, old films documenting brutal medical experiments on aliens, and find one person living on the island who Fetterman wants dead.

They then discover a lone surviving alien out for revenge, and a military intelligence plot to sacrifice them and conceal existence of the encounter. The military is concerned the shroud of mystery is about to be lifted and decide to abandon the Marines.^[1] The lone person living on the island had conducted experiments on the alien before the alien had escaped.^[2]

• Sal Landi as Lieutenant Martin Kirn
• Andrew Divoff as Captain Fetterman
• Karen Moncrieff as J.G. Watkins
• David M. Parker as Corporal Dermot Reilly
• Jim Hanks as Private Friedman
• Andrea Lauren Herz as Private Banta
• Daryl Haney as Private Hendricks
• Nigel Gibbs as Smythe
• Robert Culp as Major Guardino
• Brian Cavanaugh as Wolf
• Paul Hayes as Mr. Atkins
• Jeanne Mori as Erica Stern
• Al Ruscio as The General
• Martin Starr as Biff Atkins
• Lisa London as Melissa Meed

The film was shot in British Columbia.^[3]

Director Harry Bromley's first film in America. The movie has no direct links to the first two films^[4]

Creature Feature gave the film 3 out of 5 stars, finding that film has moments of inspiration, but finding a problem with the ending.^[5] Monster Hunter found the movie smart in theory but lacking in execution. In addition, it noted the film could be brutal.^[6] Letterbox DVD gave the film 3.5 stars out of 5, noting that while it had a low budget, and borrows some from the movie Predator (film), that there are enough original ideas to make the film worthwhile.^[7]

The film has been released on DVD twice. The first DVD was released in 1999 by Image Entertainment, who coincidentally, would release the first two entries in the Xtro series on DVD years later. In 2005, the film was released yet again on DVD by Showcase Entertainment.^[8] Both DVDs are now discontinued.^{[citation needed]}

In 2020, Xtro 3 was released on Blu-ray by Vinegar Syndrome. Extras include new interviews with director Harry Bromley Davenport and screenwriter Daryl Haney.^{[citation needed]}

• Vatnsdal, Caelum (2004). They Came From Within: A History of Canadian Horror Cinema. Arbeiter Ring Publishing.

• Xtro 3: Watch the Skies at IMDb  
• Xtro 3: Watch the Skies at Rotten Tomatoes
• Xtro 3: Watch the Skies at AllMovie