Like me, you can’t stop thinking about this. I went first to my 3-volume Franklin variorum and then to the archive.
Probably in the spring of1861, ED wrote the first version of this poem on the back of an abandoned letter, which you can see here (scroll down to see text if the manuscript doesn’t show– it was glitching of course). It uses the word Master, but also has an entirely different penultimate line, “The Vision flutters in the door -,” and doesn’t have a stanza break. But the manuscript shows that the “Vision” line was canceled out for the one with “Eternity” we have in our book. There are some dash differences to the version in the Reading Edition also.
In 1862, according the variorum, she wrote another version, and this is marked F185B and is the version that Johnson chose, his poem J461. This version adds a stanza division and changes the word “Master” to “Savior,” also using an exclamation point at the end: “Savior – I’ve seen the face – before!”
Franklin believes this poem was added to a fascicle, ED’s privately rendered books, in the second half of 1863. In this copy, his F185C which matches our Reading Edition, we have a return to the word “Master” and the dashes as we discussed them today. It makes sense to me that the version in the fascicle would be the one he used when he created the Reading Edition without variants visible, because the fascicles are seen as final copies.
This clears up the history and variants, but not necessarily the way the alternative line is a ghostly presence in the poem.
ALSO: Simpson Library has our Reading Edition available online. (Thanks, Audrey!) I’m sorry I didn’t know this before. Please use this edition to complete our assigned readings.