VFPJUDEEHZWETZYVGWHKKQETGFQJNCE
GGWHKK?DQMCPFQZDQMMIAGPFXHQRLG
TIMVMZJANQLVKQEDAGDVFRPJUNGEUNA
QZGZLECGYUXUEENJTBJLBQCRTBJDFHRR
YIZETKZEMVDUFKSJHKFWHKUWQLSZFTI
HHDDDUVH?DWKBFUFPWNTDFIYCUQZERE
EVLDKFEZMOQQJLTTUGSYQPFEUNLAVIDX
FLGGTEZ?FKZBSFDQVGOGIPUFXHHDRKF
FHQNTGPUAECNUVPDJMQCLQUMUNEDFQ
ELZZVRRGKFFVOEEXBDMVPNFQXEZLGRE
DNQFMPNZGLFLPMRJQYALMGNUVPDXVKP
DQUMEBEDMHDAFMJGZNUPLGEWJLLAETG
becomes the following after the good ole Quagmire III with Kryptos and Abscissa as the keywords. Why the repetition? Probably because Sanborn wanted to use the words palimpsest and abscissa.
IT WAS TOTALLY INVISIBLE HOWS THAT POSSIBLE ? THEY USED THE EARTHS MAGNETIC FIELD X THE INFORMATION WAS GATHERED AND TRANSMITTED UNDERGRUUND TO AN UNKNOWN LOCATION X DOES LANGLEY KNOW ABOUT THIS ? THEY SHOULD ITS BURIED OUT THERE SOMEWHERE X WHO KNOWS THE EXACT LOCATION ? ONLY WW THIS WAS HIS LAST MESSAGE X THIRTY EIGHT DEGREES FIFTY SEVEN MINUTES SIX POINT FIVE SECONDS NORTH SEVENTY SEVEN DEGREES EIGHT MINUTES FORTY FOUR SECONDS WEST X LAYER TWO
Please note the correct ending. Because of an omission of that last X it used to read ID BY ROWS. Not like we understand what layer two means anyways.
Kryptos - Beyond K4 
So if this were to mean that we were supposed to walk out and take a look at the Morse code, the coordinates would be wrong. However, it’s just about the only thing Sanborn buried on site so it is a viable direction to take. Layer two could simple mean layering the Morse code sections.
It’s gay that he used vigenere twice
Is it significant that the U misspell in UNDERGRUUND lines up vertically (ie, on the abscissa) with the X in X LAYER TWO?
Could very well be. I know it’s not what the misspellings are but where they are that is supposed to be significant. The thing I never understood was how that constituted a hint. Maybe you could draw a line between the two and then find the extra L on the Vigenere for the horizontal and it would give an xy coordinate?
I will say that after reading about duress codes/ciphers/transmission tricks, I don’t think K4 will have a misspelling. Ed was SigInt so he probably saw the sections as a series of coded messages. If he had any interest in duress codes, and if the first three sections had misspellings which was a common WWII trick then the last part will not have them thereby indicating duress which is supposed to make us dig deeper.