William Shatner, whose role as Capt. Kirk of the starship Enterprise overshadowed his other performances, says directing the new "Star Trek" movie is the most enjoyable thing he's ever done.

Shatner said the movie, the fifth on the theme, tentatively is titled "The Final Frontier" and probably will feature the return of the entire cast of the "Star Trek" TV series, including Leonard Nimoy as Mr. Spock.Shatner, speaking Saturday at a Star Trek convention in Phoenix, evaded most other questions about the film, but he did say the project has "gone from a story idea to a full-fledged screenplay."