Follows20-year-oldDrea,whoreluctantlytakesajobbabysittingforaprofessorofacollegeshehopestoattend.StrugglingtoentertaintheprofessorschildrenTrissyandJake,alongwithherownlittlebrotherPhillip,Dreatakesthemonahike,unawarethatmysteriousaliencrittershavecrash-landedandstarteddevouringeverylivingthingtheyencounter.