When a “crazy” man runs through the streets naked and with a whole bunch of gears and equipment attached to his head, he runs right into the CSI headquarters, confessing to a murder. But what he tells Mac in private right before he dies is that he is from the future and is going to kill a man named Kevin the next day. While the CSIs believe the murder won’t happen when the man who confessed is dead, they believe they are handling their most complicated case yet when a man, named Kevin, falls to his death the next day at the exact time and with the same head gears.