The frog and the scorpion.
It was a day that was raining a lot, and the flow of the river was increasing dangerously. In the middle of the river were a frog and a scorpion trapped by the flow. The frog wanted to reach the shore, but the scorpion did not leave the way free.
-The scorpion suggested to the frog: the only way to save us is to take me on your back jumping to the shore.
-The frog replied: I do not trust you not to kill me.
-The scorpion swore that he would not kill the frog and that he would never attack him for life.
-The frog, innocently, accept the deal.
The scorpion climbed onto the back of the frog and the frog started jumping towards the shore. At that moment the scorpion stuck its sting to the frog, and the two died in the current of the river. The scorpion could not avoid its natural instincts.
"Never trust impossible treatment"