Well, i do know for a fact that it has something to do with a 'day?' Athrun mentioned that his friends are acting all weird and saying if they realize what day it was. I'm thinking the anniversary of his mother's death? or his birthday? or... something...

I like where the story is going so far. I'm hyped! ^o^

Haha, this is really good Prince-chan! I wonder what Athrun will have to go through. :)

My ideas:
Someone has been hired to kill Athrun... But a mysterious benefactor who knows about Athrun's impending murder has sent some documents about the threat, etc... Tracing down the documents, Lacus learns that the sender is in Plants... Further investigations reveal that Lenore Zala might not be dead... Ooh! Sensing that that piece of information might be too much for Athrun to handle, she involves Cagalli and Kira in a plan that will include faking their own deaths (and Athrun's also), in order to anonymously go to Plants and take their enemy down by surprise.

They might actually be hiding Athrun under another identity in the hospital, since Lacus has kinda been able to lose the person(s) following them... Kira might have gone to buy the tickets to Plants... Cagalli seems to be feeling guilty because she knows that Athrun would have liked to know that his mum is still alive...

Anyway, they plan to reveal the whole thing to Athrun after one week. After their fake deaths. On their way to Plants. Hm, they haven't told him anything because they knew that he'd try to do everything on his own?

NOTE:
Sorry if it's too far-fetched... lol. But please do continue it, even if you don't use my ideas. The fic's pretty interesting :)