In a certain town, there lived a Brahmin who denounced all luxuries of life. His name was Drona, and he did not wear fine clothes, or use perfumes, or practice any lavish means. 
 
He followed rigorous practices of worship even during cold, hot and rainy seasons. Due to this, his body had become lean and weak. His hair and nails also grew long due to his absence of maintaining them. 
 
One of his devotees gifted him with a pair of calves. He took great care of the calves and fed them properly. In due time, they grew enviable fat. 
 
One day, a thief noticed the calves and thought, "I shall steal these fat calves from him." 
 
He planned and returned with a rope to steal the calves in night. On his way, he met a demon with a very hideous appearance. 
 
The thief was frightened on seeing him and asked, "Who are you?" 
 
The demon replied, "I am a demon. I always speak the truth and hate liars. Introduce yourself!" 
 
The thief confessed, "I am a thief and I am on my way to steal two calves from a devoted Brahmin".
 
The demon and the thief struck a friendship as they were both truthful to each other, and they planned that the demon can eat the Brahmin, and the thief can steal the calves. Their works will be accomplished in the same place, so they went together.