Quite a few mysterious characters were introduced in ACOS. One of these was the old man watching Carridin's palace in Ebou Dar. What do we know about him?

• He's old, and quite worse-for-wear: "A scrawny, white-haired fellow lounging nearby in the shade. Mat looked at him questioningly, and he grinned, showing gaps in his teeth. His stooped shoulders and sad weathered face did not fit his fine gray coat. Despite a bit of lace at his neck, he was the very picture of hard times." [ACOS: 14, White Plumes, 282]
• He can't remember parts of his past: "His head felt... peculiar... sometimes. Most often when he thought of what he could not remember." [ACOS: 17, The Triumph of Logic, 318]
• He's got a lot of knowledge about local DF activity--he knows about "Carridin's pretty little killer," and about the two BA in town. [ACOS: 17: The Triumph of Logic, 319]
• He used to be a fighter of some kind, and he's still proficient with knives: "His hands no longer possessed the strength or flexibility for swordwork, but the two long knives he had carried for well over thirty years had surprised more than one swordsman." [ACOS: 17: The Triumph of Logic, 319]
• He's working on some kind of deadline: "He did not have much time left, but it was all he did have." [ACOS: 17: The Triumph of Logic, 319]

In [WH: 16, An Unexpected Encounter, 355-356], Mat meets Noal Charin, whose description rings a few bells: "...a stoop-shouldered, white haired old man with a large hooked nose planted in the middle of a sad face... He was sliding a very long dagger into a sheath beneath his coat... he laughed mirthlessly, showing gaps in his teeth." Mat thinks that his (weathered) face looks familiar, but cannot place him, and notes that his hands look like they've healed wrong after being broken.

It's pretty obvious that Noal is the geezer on the barrel; the similarities between each description are too striking for them not to be the same person. So the real question is, who is Noal Charin?

An overly-complete list of possibilities:

1. Jain Farstrider - By far the most popular (and likely) candidate; see section 2.4.4, the Jain section.
2. Graendal's Old Man - In [TFOH: Prologue, The First Sparks Fall, 26], when Graendal Gates in to the Forsaken tea party, a "rumpled old man" can be seen in the room whence she came. Perhaps Noal was spying on Carridin (Sammael's flunky, at that point) for Graendal. His memory trouble could be explained by Graendal's usual use of un-subtle Compulsion. This, of course, doesn't preclude him from being Jain Farstrider as well. This possibility is further strengthened by Noal's claim that he has been to Shara; in an elaborate attempt to hoodwink Sammael, Graendal tells him about going to Shara to acquire her newest pets [LOC: 6, Threads Woven of Shadow, 136]. Coincidence? (On the other hand, Ituralde's POV in COT's Prologue makes it far more likely that Graendal's Old Man is Alsalam, the King of Arad Doman.)
3. It's unlikely, but Noal could be somebody associated with Carridin's late family-- he might just be some old family retainer or even a relative who escaped the Myrddraal and came looking for Carridin to exact vengeance for what he had done to the family. How he found out that Carridin is responsible is another question. (Maybe he looked for the only surviving family member.) However, Noal doesn't appear to be in a very vengeful mood, and there are far more interesting and non-random people for him to be.
4. Geofram Bornhald - If Geofram survived the battle at Falme, he could certainly have sustained such injuries to make him be in as bad a shape as the old man in question. Furthermore, he'd have reason to be paying attention to Carridin, considering the way their relationship stood when they parted in TGH. OTOH, the old man seems to have been unable to handle a sword for 30 years. Bornhald doesn't fit that description, nor does the physical description we get of him in [TEOTW: 30, Children of Shadow, 374] match Noal's description: gray-haired, rather than white, grandfatherly, and with "a kindly face, bluff and dignified." Furthermore, what we see of Noal's personality is nothing like Bornhald's character.
5. Old Cully - One of the local DFs is a murderous old beggar named Old Cully, and it's been suggested that this Old Cully and the barrel man are one and the same. This is not possible. Carridin knows Old Cully by sight, yet when he sees the barrel man in [ACOS: 15, Insects, 286] standing next to Mat, he doesn't recognize him. Another reason why the barrel man can't be Old Cully: Carridin describes Old Cully as having one eye and no teeth [ACOS: 15, Insects, 284]. But when Mat sees Noal in [ACOS: 14, White Plumes, 282]: "...he grinned, showing gaps in his teeth". There is no mention of him missing an eye, either.
6. Elyas Machera - Also not possible, unless he's capable of being in both Ghealdan with Perrin and in Ebou Dar with Mat at the same time.