In line 660, the Pardoner begins his anecdotal story. When the story opens, what are the rioters doing and what captures their attention?

The three drunkards were in a tavern one night, and, hearing a bell ring, looked outside to see men carrying a corpse to its grave. One of them called to his slave to go and ask who the corpse was: he was told by a boy that the corpse was an old fellow whose heart was smashed in two by a secret thief called Death.