Sam Trueheart, also known as True of Heart, is the adoptive father of David Trueheart. During the time regression of Earth, Tommy's search for his piece of the Zeo Crystal led him to Sam Trueheart's tribe. Sam aided Tommy with advice on finding the crystal, as well as providing him with half of an arrowhead, though Tommy was transported home before he could provide more detail on it. Sam would later reunite with Tommy to help him unravel the mystery behind the arrowhead, as well as introduce Tommy to his long-lost brother David.