quote:

But why the clue relating to ichor and grave dust then?

spoiler:

abcdfg ce hid jkblambnd1
c ko hid ikfdec pqdde nkbodrrk rdcakeq2 c jbchd hm rmq abmo

Yes, It appears that 'c' is either "I" or "A". And It also appears that 'hid' might be "THE"
But those are simply preliminary guesses. Further bulletins as events warrant. (Always wanted to use that line.. hehehe)

spoiler:


abcdfg ce hid jkblambnd1
c ko hid ikfdec pqdde nkbodrrk rdcakeq2 c jbchd hm rmq abmo
hid nmrf gqbaknd ma ikfde nrmhidf ce sdrsdh prknledgg1
lbmhdnhdf abmo hid bdf gqe3g gnmbnicet rctih ma ikhd kef ketdb2
c3o kabkaf hikh hid nkqgd amb ou jbchcet cg emh nkgqkr2

Looking at this, with 'c', 'ko' and 'c3o' and other clues, 'c'='I', 'k'='A' , 'o'='M', and '3'='''(apostrophe).

spoiler:

FRIENDS IN THE WARPFORCE,
I AM THE HADENI QUEEN CARMELLA LEIFANU, I WRITE TO YOU FROM
THE COLD SURFACE OF HADEN CLOTHED IN VELVET BLACKNESS.
PROTECTED FROM THE RED SUN’S SCORCHING LIGHT OF HATE AND ANGER,
I’M AFRAID THAT THE CAUSE FOR MY WRITING IS NOT CASUAL.
YOU HAVE LEARNED MUCH RECENTLY IN YOUR STUDIES, YES?
WELL MUCH OF IT MAY BE A GRAVE DUPLICITY!
BEWARE THE DECEPTION OF HAVEN AND THE LORD OF TERROR.
TRUTHS ON WHICH YOU MAY RELY ARE THESE:
LORD TERROR SERVES MONEY ABOVE ALL THINGS. HIS SECOND IN
STRENGTH IS THE SERPENTINE VAX.
VAX IS AN UNDEAD KROO’ATHRI. BUT NOT LIKE US OR THE NEKRON’S.
HIS FEAST IS THE LIFE BLOOD.
TERROR IS NEITHER A SERVITOR OF THE AUTARCH’S, NOR OF THE
NETWORK, BUT MAKE NO MISTAKE HE IS STILL YOUR ENEMY!
THE EXOS ARE CRUSTACEAN LIKE CREATURES THAT WANDER SPACE IN
LIVING SHIPS GROWN AND NOT MADE. THEIR LEADER IS THE AUTARCH
NAASERIA.
THE NEKRONS ARE MANUFACTURED UNDEAD; THEY ARE CREATED BY THE
MYSTERIOUS NECROMANCER, THE AUTARCH, DARK MADDER IN HER BID FOR
SUPREMACY. SHE HAS TAKEN MY OWN PLANET AND ITS TWIN PURGOS.
THE DARK MACHINE LIVES AS YOU DO. DO NOT LET THEIR
MECHANSTIC ORIGIN CONFUSE YOU. THEY SERVE z29k WHO IS THE
AUTARCH OF OMNUS.
JARIK Z’KAA THE AUTARCH OF THE ZIRRIX, SERVES ITS CONTINUANCE BY CORRUPTING LIFE. Z’KAA’S ABOMINATIONS ARE NEITHER UNDEAD, AS THE NEKRONS AND HADENI, NOR ALIVE AS THE NORMAL BIOTICS, BUT IN A STATE SOMEWHAT DIFFERENT FROM EITHER CLASSIFICATION.
THEY ARE CONTAGION GIVEN SENTIENCE.
I SHALL VISIT AT MY EARLIEST CONVENIENCE THERE IS SOME ACTIVITY OF THE NETWORK NEAR THE WORLD OF COREN. SHERIDAN’S NOTE: I DO NOT BELIEVE HER MAJESTY HAS MAN[Y] TERMS SPELLED CORRECTLY: SHE UTILIZES AN ANCIENT ROYAL CONVENTIONS.


EDIT: I leave it in this format. According to Falerin, the conventional upper and lower cases are not different in this symbol code.
EDIT2: Fixed punctuations.
EDIT3: Thanks IRC guys for help!

spoiler:

Step 1: Translate the sign language into numbers:
79777968 778487 8370758971 8477 714881 87488268656589787674 8477 678479707890827469

Step 2: Translate the numbers into ASCII:
OMOD MTW SFKYG TM G0Q W0RDAAYNLJ TM CTOFNZRTE

At this point we find the first anomalies. The zeroes should actually be N's. The ASCII code for N is 78, the code for 0 is 48. An easy typo when using the 10-key numpad. Eldron also made a correction to the second "TM." So the true code is:

OMOD MTW SFKYG TM GNQ WNRDAAYNLJ GQ CTOFNZRJE

Step 3: A modified Trithemius cipher, which is what we used to solve the braille cipher a while back. But instead of shifting once per letter, it shifts twice.... for the most part. Again, there are anomalies in the key. A perfect Trithemius key would look like this:

aceg ikm oqsuw ya ceg ikmoqsuwya ce gikmoqsuw

But the anomalous key turned out to be such:

aceg ikm oqsux za ceg ijmoqrtvxz bd fhjknprtu

Which gives us this cipher text:
OKKX EJK EPSEJ UM EJK OEFPKJFSOK FN XMFVAKAQK

Step 4: Simple letter substitution. The final plaintext is as follows:
SEEK THE TRUTH IN THE STOREHOUSE OF KNOWLEDGE

spoiler:

I love the names of the Hadeni: Queen Carmella Leifanu and Sheridan. Heh. Perfect references for a race of darkness.