I came across something in my reread of AGOT. It is in one of Dany's last chapters, the one when Khal Drogo is injured and she meets Miri Maz Dhur. She is told by Miri Maz Dhur that she has some healing powers and learned it in Asshai. There she met a maester from Westeros named Marwin who taught her some things of his lore. Jorah confims to Dany that this Marwin would have been taught in Oldtown and indeed is a maester with knowledge of how to heal wounds and sickness. Fastforward to AFFC and we finally meet this Marwin in the Citadel in Oldtown through Sam. He is with Pate and has light an obsidian candle. This Marwin appears as a renegade type in the Citadel with interests that lie somewhat hidden. He is seen as a link to Dany. What do we really know of Marwin and the bigger question is what is his purpose? Was the fact that Miri Maz Dhur met him in Asshai sometime before she met Dany purely coincidental? GRRM could have used any name or no name at all and just said that she met a maester. But, the fact that he took time to name him and then introduced him later must mean something. Is he linked to the Faceless Men as well with the presence of Pate (Jaqen)? This just feeds my speculation that there are greater hidden forces at work in ASOIF.