The Pardoner is a manipulative, arrogant fool who is traveling with the other pilgrims to Canterbury. He's a sinner by his own choice which he freely admits to the other travelers. As a pardoner he sells his divine pardons to all, including this group. Basically, he's a self-proclaimed absolver of sins. Okay, any one up for confessing anything to that guy? Uh...no.
He tells a tale about three young men and goes on a tangent about the carousing the young embark on i.e. drinking, partying and gambling. In short, the young are often a target for the devil and usually fall victim to gluttonous pastimes like the ones mentioned above. These three young men choose a life of crime and with each passing day, their sins increase. One day as they plan to steal gold, two of the thieves decide to kill the third guy to increase their lot. The dastardly duo devised a plan and then waited patiently. The third unsuspecting thief had a similar idea and decided his take would be greater if he killed the other two partners. He chose poison as his weapon and purchased some to do the deed. Now, wouldn't you know that they all ended up killing each other? First, the two stabbed their young friend and to celebrate they drank his tainted wine. HAH! How's that for karma?
Afterwards the Pardoner boasts the importance of purchasing pardons to repent from being sinners or becoming victim of the devil's works. He's has no shame which you can read for yourself (The Pardoner's Tale verses 442-455):
442 Now, good men, God forgive you each trespass,
443 And keep you from the sin of avarice.
444 My holy pardon cures and will suffice,
445 So that it brings me gold, or silver brings,
446 Or else, I care not- brooches, spoons or rings.
447 Bow down your heads before this holy bull!
448 Come up, you wives, and offer of your wool!
449 Your names I'll enter on my roll, anon,
450 And into Heaven's bliss you'll go, each one.
451 For I'll absolve you, by my special power,
452 You that make offering, as clean this hour
453 As you were born. And lo, sirs, thus I preach.
454 And Jesus Christ, who is our souls' great leech,
455 So grant you each his pardon to receive;
The Pardoner...he has some nerve, huh? Are you becoming a fan of Chaucer yet? Are my posts too long winded?