官方公布的主要简介说的是In season three, James Cole and Cassandra Railly embark on a desperate search across time to find the man responsible for the apocalypse, a time traveler who calls himself the Witness. Killing the Witness will mean saving the world. But the journey will come at tremendous personal stakes for both Cole and Railly and will cal into question new alliances, old bonds and the virtue of the mission itself.
