^Aye. Stephen Griffiths I'm sorry, but I can't be friends with you anymore. JK you don't have a giant stuffed mog ...or do you...?
:seifer:
Taking this topic seriously as well I'm going to go through and explain how each choice
could be a spy, I'm not saying I believe most of these I'm just trying to show how they
can be a posiblity.
Cloud - "Ex-ShinRa eh? ...I don' trust ya." A mercenary for hire with past ties to ShinRa who you don't know much about except a voice that keeps talking to him and could in fact be ShinRa talking to him via a remote device in his brain. He doesn't care about blowing the first reactor up "once this jobs over, I'm outta here." Of course by the time they start freaking about a spy its kinda already revealed that Cloud is interested in settling the score with Sephiroth more than anything. Perhaps hes still being controled by ShinRa sent to gather information, possibly even kill Sephiroth the rogue SOLDIER. Plausable
Tifa - Because she dresses like a porno slut. - Reasoning in the mind of somone who simply doesn't like her/is jealous of her sex apeal. Though like Scarlet she could be a hired beauty to take AVALANCHE down from the inside...oh yeah thats right she HATES ShinRa because of the Nibelheim incident! Not guilty, you are free to go man, say what are your plans later tonight? Maybe dinner, me, you, yeah, no?
Aeris - ShinRa wants her so baddly they can smell the flowers and Tseng has personal feelings that are getting in the way of bringing her in...Perhaps this is just a gimmick and Aeris IS a part of ShinRa, Tseng is her contact giving orders. Good on the outside, but a spy on inside...Hipocrite. Plausable.
Red XIII - An experiment for Hojo or really just a slave to ShinRa doing thier bidding on account of black mail? One false move and Cosomo Canyon's ruins become tombstones for those there. Plausable
Yuffie - A Ninja, a master of stealth and deception she decieved them once for thier Materia, why wouldn't she do it again to ShinRa? Does she really hate ShinRa or is Wutai is just being controled by them since they lost the war and are really training Ninja SOLDIER's there. Oh yeah...optional character and if an optional character was the spy the story wouldn't be able to carry on...unless like the Date mechanics it just chooses the next most likely person in line, poor Cait. Plausable.
Vincent - Ex-Turk, to trust or not to trust? Alseep in a coffin for 30 years repenting his sins or really placed there before AVALANCHE reached Nibelheim on a whim that they would solve the riddle and free this man who would later accompany them only to report back to *in a high pitch opera voice* 'ShinRa'. Plausable
Cid - A foul mouthed pilot with a passion for the skys and a dream of the stars. ShinRa suspended that dream, perhaps they are using it as black mail while he does spy work. Plausable.
Cait Sith - A bad fortune teller who shoves his way into the group just to see how his prediction turns out. Hmm... A bit suspicious fortune tellers are usualy never that involved in thier work. But look at him hes all cushy and cuddly and look at those inocent eyes, he would never betray...tho the rabit in Monty Python and the Holy Grail did turn out to be a vicious killer. Plausable.
Now we bring in the witnesses. What's that, we have no witnesses?

(I've been waiting all reply to use that image)
To be honest I after things started going tits up and the idea of a spy came about, I didn't really sit around and think about it trying to weed out who was the spy as if not using them in party battles or killing them in a battle would solve the situation anyway. Like Cloud I kind of had the 'I don't even want to think about there being a spy I trust everyone' mentality, thus I kept on playing, bound to figure out anyway. Honestly though I did sorta suspect Yuffie because of the past incidents because I found Wutai on accident looking for the Temple of Ancients...ah cutscene this must be the right place...wait what...no materia *brain explodes*