“Send Help” (** out of four) was a disappointing horror melodrama about an employee (Rachel McAdams) and her smug boss (Dylan O’Brien) who crashland their plane and are stuck on a deserted island where they must put aside their differences to survive but are at the same time constantly outthink and outsmart one another. Director Sam Raimi mixes in some of the tongue-in-cheek horror of “Evil Dead” and “Drag Me To Hell” with the moral quandaries of “A Simple Plan” but lacks those films’ incendiary spark; ultimately the film it reminds you most of (and rips off) is Robert Zemeckis’ “Castaway.” McAdams’ usual rock-solid performance can’t even really keep this one alive.