On each episode, three competitors from a previous season of Alone are issued a challenge by a fourth prior competitor and are given 3 days to complete the challenge prior to judgement on the fourth day. The fourth competitor sets the overall challenge, sets three criteria for judgement, selects the toolsto be provided and selects the winner at the end. Each of the three are provided with an identical set of tools they may use in completing the challenge in addition to the natural resources available to them plus anything they have with them. Each of the three competitors complete in their home location and self document their progress. There is no prize for winning a challenge.