From parallel waves or eight chain thru formation: All arm turn half. New centers arm turn 3/4 and then as the centers of the wave across the set start their Trade, the lonesome ends facing in join the centers in a four hand star. The lonesome ends use the star as a means of crossing to the other side of the set so they can return to their original wave to face out (as though they had done an Ends Trade). The original center two complete their part of a regular Spin Chain Thru. Meanwhile, the lone end facing out Trades to the other end of the original wave. Finishes in parallel waves.
Fan Chain The Star (author unknown): Do all the moves in Spin Chain The Star after the initial half arm turn.