The tavern-knave and the publican both know exactly who has died. The tavern-knave tells the three brash young men that Death has taken a friend of theirs. He goes on to warn them that they should be wary of Death because he is such a strong adversary. The publican goes on to say that Death lives around there and that he might dishonor the young men if they aren't careful. The publican is the one who tells them which village to go to in order to find Death. The tavern-knave and the publican clearly know more than people would about Death. Later, when the three men encounter an old man whom they verbally abuse, he, too, is Death personified. Death is leading the three young revellers to him and he is successful by taking advantage of their greed.
Chaucer’s “The Pardoner’s Tale” is full of surprises and unexpected twists. In fact, the Pardoner himself, who tells a cautionary tale about the danger of greed, is greedier in a more despicable way than any of his own characters—he tricks people out of their money by capitalizing on their desire to win favor with God.
When the three rioters enter the tavern, they encounter a young employee, the tavern knave. The tavern knave, by his speech, quickly shows that he is not just a kid clearing tables. He seems to be expecting the rioters and offers them some advice that belies his age, when, speaking of death, he says:
To meet him, sire, be ready evermore.
Although Chaucer does not explicitly say so, it seems that Death has disguised himself as this tavern-knave to get the rioters moving toward their own deaths.
The publican then completes the trap by telling the rioters where they can expect to find death:
This year he’s left for dead
In just one town (a mile from here, I’d gauge)
Both man and woman, child and knave and page—
I think his habitation must be there.
The rioters then head off in a fever to find death, who they encounter on the road, this time personified as an old man.