He tossed his head and stepped into a trot toward the open gate.
Metta yelled in triumph.

The rider tossed his own head in rhythm to Dexter's trot.

His whole body tossed in the saddle; it was a fearsome pace; the sensations were like nothing he had ever dreamed of.

And he was so high above the good firm ground! Dexter continued his jolting progress to the applause of Metta.

The rider tried to command Metta to keep still, and merely bit his tongue.
Stirred to life by the tickling, Dexter now became more acutely aware of that strange, restless burden on his back, and was inspired to free himself from it.