Now, I've posted this on a certain other WoT forum before, but as the post seems to have disappeared, I'll have to start from scratch. For the record, this does contain spoilers for The Gathering Storm. The first evidence that Taim is not exactly as he seems is the first time we see him. In Lord of Chaos, when Taim comes to meet Rand, there are several indications that something isn't right. The first is Lord Bashere, who should have recognized Taim on sight from fighting him for so long, expresses doubt as to his identity. Taim claims he shaved, and then goads Bashere with the recounting of something that he did to some of Bashere's men, making fury cloud his recollection and dispel his doubts. Taim then makes an offer of equal partnership to Rand - something that harks back to the prologue of The Eye of the World. The second blunder Taim makes is talking like someone from the Age of Legends. Everyone should be familiar with the 'so-called Aiel' statement that set so many people on the wrong track (Demandred) until the Cleansing and Jordan himself cleared that up. There are other things Taim knows that he shouldn't. When Rand weaves a gateway, Taim is unsurprised, and doesn't ask for the weave to be shown a second time, as somebody might who had never seen it before. He then calls the weave 'Traveling', when Rand told him it was called a Gateway. His excuse for knowing how to identify another man who can channel is paper-thin at best - how without years of study (or at least an Aes Sedai with whom to compare notes) would he ever have come up with something that takes so long to test for? Next, we must examine the evidence against this theory - most importantly, Taim's height vs. Moridin's height. We know from people's observations that Moridin is a tall man, around the same height as Rand himself. But Rand observed that Taim had a height which was 'just above average'. He certainly wouldn't have thought that if Taim was anything close to his own height. In that first meeting, Bashere's soldier's spear touched Mazrim Taim. I believe there was further physical contact later on. This is not necessarily inconsistent with the effects of Mask of Mirrors. What part of Taim did the spear touch? It certainly didn't go anywhere near his head. If anything, as long as the clothing Taim wore was not different underneath the Mask, the spear would have touched him lower on the chest than it appeared to - still a solid target - and nothing would appear to be wrong. If there were hand touches involved in testing the Asha'man, those can be explained by a simple difference of the angle of his arm. A taller man's hand doesn't fall too much higher than a shorter man's because it is also longer; a clever enough Mask would find this no problem. But Taim's height itself is inconsistent. Though Rand clearly sees him as average height, Perrin and Elayne have surprisingly different opinions. At Dumai's Wells, when Taim shows up with the Asha'man, Perrin observes that Taim is just shorter than Rand. Elayne also, in her first meeting with him in Caemlyn, thinks that Taim is of a height with Rand. Perrin, of course, actually saw them standing side by side (It might have been on a hill, but knowing Perrin's attention to detail, I doubt he would have missed that). Elayne may not have seen them together for comparison, but one would think she'd know the height of a man she spent copious amounts of time kissing in the Stone of Tear. Another thing to note - if Moridin is disguised as Taim at the first meeting, he would probably have to be wearing a True Power disguise, not a Saidin one, because even inverted weaves can sometimes be detected (although some Forsaken have made this mistake before *coughSemirhagecough*). Only Moridin could use the True Power at this point - which brings me to my next piece of evidence. In the same meeting in which Elayne notes Taim's height, she notices a darkness around him. The description is almost identical to that which follows Rand when he has embraced the True Power. The rest of the evidence pales in comparison to this one fact, but I will mention a few more minor points briefly before concluding. Moridin's colors being used in the Black Tower's decorations. A known Shadow motif in the same. The famous 'Let the Lord of Chaos Rule' line. The dark look in Taim's eyes when he states that he'd dearly like to know which of the Forsaken had sent the Grey Man to kill Rand. Taim neglecting to point out Dashiva as a man who might be a Forsaken, despite claiming that he 'learned very fast', and the fact that Dashiva was even there in the first place, and happened to be hanging out near Taim, when we all know whose orders he'd been taking. Moridin almost always seeming to know what Rand is up to, and to not be at all concerned about the Asha'man, even though he apparently hasn't delegated anyone new to looking after them since the death of Osan'gar. Finally, whenever Rand sees a face in his mind - the one associated with the sickness while seizing Saidin - it is hazy or obscured, save for two instances; one in the manor house in Tear, and one right before Rand channels the True Power through Moridin's link. Again after this experience the face appears hazy, almost as if some power were obscuring it part of the time, but not all. If the image is hazy because Moridin spends most of his time disguised as Taim, through either a disguise of the True Power or of inverted Saidin, this is a perfect reason for the obscurement to be intermittent instead of simply dissipating. I believe I have covered all the major arguments. If you know of one I haven't squashed yet, feel free to chime in.