And, as his strength Failed him at length, He met a pilgrim shadow—
We learn more about the knight's aging with these lines.
Eventually ("at length"), his strength gives out ("Failed him"). That's the bad news. The good news? He's met someone, er, something: a "pilgrim shadow."
Oh, nevermind. That's more bad news. This shadow makes it sound like the knight is getting closer to death. You could, if you really wanted to, even argue that the knight has just died. This poem is starting to get a little eerie.
Let's back up for a second, then. What, exactly, is a "pilgrim shadow"? (Hint: it's not a shadow of one of the Pilgrims who came over on the Mayflower.)
Nope. A pilgrim is not just somebody with buckled shoes who showed up to the first Thanksgiving. It's anyone who travels on a journey, usually as on a quest for something.
So, this shadow could be a number of different things. It could be a wandering ghost (the word "shadow" suggests that it might be a spirit or shade of sorts).
Or, it could also just be another guy searching for Eldorado, someone who's wasted away like the knight and become a "shadow" of his former self.
If the pilgrim is like the knight, though, maybe this shadow is the knight himself, or perhaps his soul, or something like that. Sheesh. This is bizarre. But then again, what did you expect with Poe?
"Shadow," said he, "Where can it be— This land of Eldorado?"
Here the speaker actually addresses the shadow. He's asking for directions—finally!
The tone of the speaker's question expresses bewilderment. It's almost like he's saying "Where can it POSSIBLY be, this Eldorado?" (We bet the speaker's voice sounds something like Luke Skywalker's in Star Wars when he screams "WHERE CAN HE BE?! 3PO!")
This conversation between the speaker and the shadow doesn't really clear up the mystery of the shadow's identity, though, does it? Let's read on…