“Monolith” (** out of four) was a monotonous action melodrama about a single mother (Katrina Bowden) who becomes stranded in the middle of the Las Vegas desert with her newborn child when she is en route to see his father which physically and mentally tests her will to survive. Bowden’s good performance can only carry this so far as the story starts to dawdle and run out of steam in the middle, and never fully regathers itself. Moody electronic score by Diego Buengorno.