Amazon is offering up Star Trek IV: The Voyage Home for purchase for only $3.99 through their Video On Demand service.

This digital deal is only for today, Thursday, September 23, beginning at midnight PST and runs for 24 hours, so grab it while you can. The digital version is regularly $9.99, and the 24-hour rental is $2.99.

Visit the Star Trek IV: The Voyage Home product page to purchase the film.

Released in 1986, in this fourth film in the franchise, which was directed by Leonard Nimoy (who also stars as Spock), James T. Kirk (William Shatner) and the crew of the Enterprise go back in time to the year 1986 in an effort to save the Earth! People, there be whales in this movie!

To save Earth from an alien probe, Kirk and his crew go back in time to retrieve the only beings who can communicate with it, humpback whales.

I love me some Star Trek IV, which is famous for its environmental message, something that wasn’t all too common in movies back in 1986. The filmmakers even consulted with Greenpeace on the film. Not only is the 23th century Enterprise crew out of place in the 20th century, but also Spock is not himself after the events of the previous film, both aspects of which lead to some humorous dialogue and antics.

Visit the Video on Demand page to learn more about the service (you can stream the film right on your computer, or download it to you PC, and more).