"THERE AREN'T ANY TRAILS at all where you're pointing," said the captain. "Remember, we fought our way up that mountain to capture it in the first place. That area directly behind the abbey is almost sheer cliff. No one could climb it."

Chico shook his head stubbornly, his face determined. "Goats climb it, sheep climb. And once before, just last year, Chico climbed it!"
The major patted the boy's thin shoulders. "I think you'd try it," he said quietly. "I honestly think you would. But it's no good."
"What's no good?"
"It won't work. You couldn't make it alone. And you couldn't bring Missouri down, even if you got to him."
"I don't go alone!" Chico cried desperately. "I go with Sergeant Donkey."

Young Chico Felipo and his brother and two sisters have come through four long years of World War II in Italy. First all the able-bodied men were recruited from San Palio, then the Germans came and occupied the village, and now the Americans are using it as a Remount Depot to prepare pack animals for the mountain fighting. Chico becomes friends with an American officer named John Price, (known as Sergeant "Missouri,") who is also a farm boy. Their friendship includes a mutual affection for a brave little donkey, recovering from a bullet wound. Now, Missouri is in danger, and Chico and "Sergeant Donkey" must try to help...