Moebius 17

Two young men tag (spray paint) a train involved in a multimillion dollar subway project, a project that likely involves political payoffs. Since they have to run from security staff they cannot take pictures of their work, so they go back the next day to snap a pic. But the train has disappeared. They know it has indeed physically disappeared because they find the security staff frantically searching for it as well-- because its absence, if disclosed to the public, could lead to investigations that might expose the corruption. One of the taggers is the son of a quantum physics professor, and begins to believe that the new subway construction has opened the door to an alternate reality. He believes that every aspect of our present reality is only a probability, the alternatives of which reside in other dimensions that may affect our own.