There was a huge Banyan tree beside a lake, which nested a number of cranes.
In the hollow at the foot of the tree lived a poisonous black snake. He used to climb up and eat the crane's youngs after they were hatched.
One crane, who had lost her children to the cunning black snake, started weeping on the banks of the lake.
A crab, who was nearby, heard the crane weeping, and asked, "Why do you cry, aunty?"
The crane replied, "I am the unlucky mother, all of whose children have been eaten by the wicked black snake, who lives in the hollow of the tree. What else can I do but weep? I would have killed the snake if I could!"
The crab thought for a while, "I have to devise a plan to have the black snake killed, and have the cranes destroyed at the same time. The cranes are our natural enemy. I will tell him half truth and half lies, to my advantage."
