Mystic Blue Blood, a drink not so popular due to its odd color and unrefined nature, more so in a bar of such a caliber where the mercenaries and slavers came to blow off some money. So why would such a cheap drink be here?
Obviously, it was a code word, specifically the subsequent lines spoken by the guard who was alone at the moment and the old woman who was not a familiar face to Darde, but this didn't make him curious.
This is a good thing for him, a good opportunity to use this woman as his entrance towards Lady Emira's room.