Dr. Alam, a very profiled specialist in neurology and a successful surgeon, is drowned in his professional and social work, in a way that he has totally forgotten all about his son Saman. Samantha the beautiful nights of desert with it starfull sky attracts Saman to itself and the young boy falls in love with night sky and observation of stars. Due to an event the doctor leaves his profession and work behind and goes through the desert to find his son.
After their father (Tim Robbins) is called into work, two young boys, Walter (Josh Hutcherson) and Danny (Jonah Bobo), are left in the care of their teenage sister, Lisa (Kristen Stewart), and told they must stay inside.
Disgraced Navy SEAL Shane Wolfe is handed a new assignment: Protect the five Plummer kids from enemies of their recently deceased father -- a government scientist whose top-secret experiment remains hidden in the kids' house.
After a tragic accident, six friends reunite for a caving expedition. Their adventure soon goes horribly wrong when a collapse traps them deep underground and they find themselves pursued by bloodthirsty creatures.