Zac Efron
(© Joseph Marzullo/Retna)
Zac Efron
(© Joseph Marzullo/Retna)
Justin Martin, Jemma McKenzie Brown, and Matt Prokop will join previously announced stars Zac Efron, Vanessa Hudgens, Ashley Tisdale, Lucas Grabeel, Corbin Bleu and Monique Coleman in High School Musical 3: Senior Year, a feature-film follow-up to the two popular Disney television movies, according to TVGuide.com. The film is set to be released on October 28.

HSM 3, which will be directed by Kenny Ortega and scripted by Peter Barsocchini, finds high school seniors Troy and Gabriella (played by Efron and Hudgens) "facing the prospect of being separated from one another as they head off in different directions to college. Joined by the rest of the Wildcats, they stage an elaborate spring musical reflecting their experiences, hopes and fears about their future."