Midnight
`` Good enough ! You 're on ! '' they shouted in chorus , and loped away . As they passed the handicap mark , another shrill , defiant yell came floating back to where Kitty sat reining in her impatient Midnight . At the signal , the two ponies leaped from a lope into a full run , while Kitty loosed the restraining rein and the black horse stretched away in pursuit . Spurs ring , shouting , entreating , the two lads urged their sturdy mounts toward the goal , and the pintos answered gamely with all that they had . Over knolls and washes , across arroyos and gullies they flew , sure-footed and eager , neck and neck , while behind them , drawing nearer and nearer , came the black , with body low , head outstretched and limbs that moved apparently with the timed regularity and driving power of a locomotive 's piston rod .