The end result of all this lunacy is that giant, technologically advanced super-sharks will stalk you through a maze of underwater corridors, not because they just want to eat you- they're too smart for that until the final scene- but solely in order to manipulate you into letting them out so they can complete their master plan and annihilate the human race. But have no fear- at the very last moment, right when it's especially important for the plot, the evil master shark will forgo its plan for world domination solely to stuff its gullet with human flesh one more time, even though it already ate Samuel L. Jackson.
Speaking of Samuel L. Jackson, he should have been safe at the time, because he wasn't even in the water. He was busy giving an inspirational speech, right up until the moment that the evil shark queen jumped completely out of the water, surfed along the corridor for a few feet, chomped him completely in half, and then slipped back in the water.
To sum up, this is a gritty and realistic social drama, and I highly recommend it.