An Eagle swooped down upon a Serpent and seized it in his talons
with the intention of carrying it off and devouring it. But the
Serpent was too quick for him and had its coils round him in a moment;
and then there ensued a life-and-death struggle between the two. A
countryman, who was a witness of the encounter, came to the assistance
of the eagle, and succeeded in freeing him from the Serpent and
enabling him to escape. In revenge, the Serpent spat some of his
poison into the man's drinking-horn. Heated with his exertions, the
man was about to slake his thirst with a draught from the horn, when
the Eagle knocked it out of his hand, and spilled its contents upon
the ground.

"One good turn deserves another."