The old man wrote a letter to his son and described his predicament:
I am feeling pretty bad because it looks like I won't be able to plant my tomato garden this year. I'm just too old to be digging up a garden plot. If only you were here, my troubles would be over. I know you would dig the plot for me.
A few days later he received the following letter from his son:
I'm sorry I'm not there to help you, but please don't dig up that garden. That's where I buried the bodies.
The next morning, the police arrived at the old man's house and dug up the entire area. However, they didn't find any bodies, so they apologised to the old man and left.
That same day, the old man received another letter from his son:
Go ahead and plant the tomatoes now. That's the best I could do under the circumstances.