Born and raised in Dallas, Texas, Thomas was an exceptional running back at Lincoln High School in the mid-1960s.

He continued his success at West Texas State University in Canyon, playing fullback alongside Mercury Morris, while running through defenses for Joe Kerbel's teams.

"[5] He had 18 rushes and four receptions for 37 and 21 yards respectively, caught a 7‐yard touchdown pass as Dallas took a 13–6 lead in the second quarter and fumbled at the Baltimore Colts' one‐yard line in the Cowboys' first possession of the second half.

[8] Within a week, because of problems with the Patriots and head coach John Mazur,[9] in an unprecedented move NFL commissioner Pete Rozelle voided part of the trade, sending Thomas and Garrett back to their original teams.

Thomas returned to the Cowboys, but decided to keep silent all season long, refusing to speak to teammates, management, or the media.

He also was named All-Pro and led the Cowboys with 95 rushing yards and a touchdown in Dallas' 24–3 win over the Miami Dolphins in Super Bowl VI, the franchise's first.

In a postgame interview following that Super Bowl, CBS television announcer Tom Brookshier noted Thomas' speed and asked him, rhetorically, "Are you that fast?"

[13] During the 1972 off-season he became even more isolated and insubordinate, so he was traded to the San Diego Chargers for Mike Montgomery and Billy Parks on July 31, 1972.

A Publishers Weekly reviewer of the book commented, "The title implies, although the text nowhere suggests, that there is a relation between the fate of running back Thomas and the decline in the fortunes of the Dallas Cowboys.

Thomas, when he appeared on the professional football scene in 1970, was acclaimed as an outstanding player but within two years was stigmatized as an 'emotionally disturbed misfit', largely because of his periods of total silence.