What is it, then, between us? What is the count of the scores or hundreds of years between us?
These lines might be our favorite in the entire poem. He asks, "What is it, then, between us?"
You could imagine that he already has an answer in his head – "not much" – or you could imagine he asks the question seriously, as if he were surprised that there could still be something keeping us apart despite his time-traveling powers.
In line 59, he moves closer to the implicit answer that time can't really separate people.