Because he can't let sleeping dogs—or horses as the case may be—lie, Mutt continues taunting Sean right up until the start of the race. He says "I know what you care about, Sean Kendrick," (61.13) with his beady little eyes locked on Puck. Ruh-roh.
We shift to Puck's perspective before the chapter closes, where we see Peg Gratton give Puck her colors. "Now you wear Thisby's colors," (61.21) she says.
Puck has a hot second to feel included before the races begin.