Star Trek: Hidden Frontier was a Star Trek fan film project. Produced on digital video, the show's sets are almost completely virtual, using a green-screen chroma keyed process to place performers into virtual settings. The series is set during the era of the Star Trek: The Next Generation series. Episodes revolve around the starship USS Excelsior, and its home base, Deep Space 12, which is located in the Briar Patch, a region of space introduced in the film Star Trek: Insurrection. Hidden Frontier has produced 50 episodes, and focuses on character relationships, including gay and lesbian characters and subplots. Produced by Rob Caves, Hidden Frontier ran for seven seasons and was produced by volunteers in Southern California. The final episode of the series aired in May 2007. Two new spin-offs, Star Trek: Odyssey and Star Trek: The Helena Chronicles, also produced by Rob Caves, take place shortly after the end of Hidden Frontier.