The flask is clearly one of a kind, lovingly crafted by a master hand. An ornate engraving dances between the gold and jeweled exterior: Care of MB, esquire.
Tome Unlock: The flask is found in High Elf chapter 1 on the ground near the Dusty Tome for the Tomes of Knowledge I quest. I have seen it on the right near the tower amongst other flasks and on the left near the trees on the cliff. Right click on the flask in inventory to trigger the unlock. 39.85k, 1.69k in Blighted Isle
This tome unlock contributes to the The Mysterious M.B. pursuit.