In the present day, a group of people wash up on a beach on the West coast of the United States. These are not merely people who have been involved in an accident at sea, but people from the future who are seeking refuge in a prior time—a time when people were more free.
The main element of transhumanism in The Crossing comes in the form of "Apex," a kind of gene therapy or mutation that causes those people to have heightened abilities, or to be "superhuman," if you will. One of the main characters possesses super strength, speed and eyesight, among other traits.
Time travel is a major component of the storyline.