William Dane and Silas Marner were such close friends that they even nicknamed them "David and Jonathon."
However, William had a dark heart. One day when the deacon of the town got ill and everyone in the congregation volunteered to take turns and take care of him, a bag of money dissappeared from the deacon's room upon his death.
The people said that Silas's knife was found also on the bedside of the deacon. The money bag was found in Silas's room. Everyone declared that he was guilty. However, Silas knows that the knife had been used by William and probably he took the money as well. The result was that William accused Silas as well, took his girlfriend (whom he married and he used to criticize) and she even married him.
In the end, Silas left his town in shame and discredited with a bitter anger against the world, and with a deep and sickening wonder about what could have possibly happened that night.