Zac Efron reunited with his Hairspray co-stars Brittany Snow and Julianne Hough, and director Adam Shankman in Los Angeles on Thursday (10Oct13), when they enjoyed an early Halloween trip to the Griffith Park Haunted Hayride. Hough's brother, Derek, also joined the group and shared a photo of the old pals online, alongside the caption, "Great time last night with great friends." The night out marked Efron's first in L.A. since news of his recent rehab stint became public.