When Filmax introduced Judith Colell’s “Frontier” (“Frontera”) to buyers at Cannes, the WWII thriller drew attention and was ultimately picked up for North American release via Menemsha Films. It follows Manel Grau, a Spanish customs officer in 1943 who defies Franco’s orders and risks his life to help Jews cross from Nazi-occupied France into Spain, a decision that reawakens the wounds of the still recent Civil War. A Spanish-Belgian co-production between Coming Soon Films, Diagonal TV, Crespeth Films and Bulletproof Cupid, “Frontier” will be release by Filmax in Spanish theaters on Dec. 12, following its world premiere at the Valladolid...