But we might also think at the beginning that it is a ghost tale. Our hero has an unusually bright 10 year old daughter who is talking to ghosts in her room, apparently receiving messages from them in code. After the drone incident, where we know our place in history, she figures out that the code is binary for location coordinates. That night, she and her father hunt down the coordinates, which lead to an old NORAD site that apparently has been abandoned. They quickly find that it has not been abandoned, but taken over secretly by NASA to find a way to transport humans to another world, because they know, unlike the regular populace, that it is doomed. They have hopes to do this because a worm hole has been opened up near Saturn by an unknown intelligence that permits them to travel to another galaxy where Earth -class planets might be found. What they have not figured out yet is how to use gravity as a power source to lift the millions still alive to this new planet.
It is a long and involved movie and I would have to spend many more paragraphs to sketch it out. What we find, however, is that the unknown intelligences are humans in the distant future who have mastered the fifth dimension, where time might be treated as space. The key to gravity is to be found in a black hole, into which our hero enters, only to emerge in the bedroom of his 10 year old daughter (who is 40 in our world), where he desperately tries to tell her the secret to gravity. It turns out, then, that it was the father of the future who was the "ghost" sending her messages in the present. Eventually, the 40 year old daughter picks up the watch that the father had given her before he left, and she discovers that he is sending her the needed information in code through the ticking of the watch. Humanity is saved and father and daughter have an unusual reunion at the end that stretches across decades.
But the essence of the movie is in the watch, or what it stands for, and in gravity. The watch is the father's love, which is characteristically portrayed in maudlin Hollywood style (we must not lose sight of it, though) and gravity is the attractor - of planets, of people - in fact, it is the outside world's reflection of love. Like love, it can transcend time and space, just as the love of father and daughter did. And like love, it is the answer to our problems.
Although I should not say "like" because love and gravity are different expressions of the same thing. As a female astronaut hero says (my paraphrase) "it might be that our emotions, that love, is a reflection of a greater reality that we do not understand." So, while the movie offers a lot to sci-fi lovers and relativity and quantum mechanic fans, it's essential message is this: what we are is a reflection of universal principles, the greatest of those being the attraction towards each other and all things - love - which reflects the basic unity of the cosmos that stretches beyond time and space.
Who would have thought a sci-fi thriller would be a spiritual exercise? (albeit somewhat hidden. Not one reviewer seems to have picked up on it. But then again, so it is hidden in our lives.) Then again, it is a movie that strives for greatness and sometimes (but certainly not always) achieves it. To do that, to arrive at greatness, one has to reflect on great things, and nothing is greater than the human spirit and the force that inspires and transcends it. FK