“Last Survivors” (*1/2 out of four) was a curiously flat and unaffecting melodrama about a father-and-son (Drew Van Acker and Stephen Moyer) whose solitary existence in the wilderness is disrupted when the son meets and falls in love with an outsider (Alicia Silverstone) and the father feels the need to kill her to continue their existential solitude and the son in turn feels the need to protect her. Potentially intriguing storyline is bungled by muddled script and direction that yields little emotional power or tension. Silverstone’s usual strong performance and Julian Estrada’s crisp cinematography are film’s sole virtues.