There was these three people you see, who were on the run from these soldiers who were trying to kill them. They had just enough time to run into a barn.
In the barn they found piles of sacks as the farm had brought in its crop of potatoes, so they hid in some empty sacks in with the other three piles of full sacks.
They only just had time to still themselves when the soldiers came in.
One of the soldiers checked the piles of sacks while the other went to check the rest of the barn and then went back outside. The soldier gave a sack a nudge from the first pile and the soldier heard something move, so the first man made a sound of a mouse, which convinced the soldier it was not a man in there, and he went to check the second pile of sacks.
He nudged one of the sacks and the man inside the sack in that pile made the noise of a cat which also convinced the soldier, as he was in a hurry to move on as they were not too sure if the men were there or not, and they had a lot of ground to cover.
The soldier went to give the third pile a nudge, and with that, he heard the third mans voice say "Potatoes!"