Immer holds up the arrows. Well, he technically levitates them above the gathered.
This was their warning shot.
A shadow appears on the wall.
And this is how it was recieved.
The shadows play on the wall so that it looks like the wall of the town. Two figures stand atop it. An arrow appears, flying towards the figures. One falls off the wall, and swoops to catch the arrow. The shadows dissapear.
These arrows are of elven make. This means two things. One, we have enemies among the elves. Two, those enemies are unafraid to hurt us.
An elf appears in the shadows. Next to him is a smaller figure. The elf is violently attacking the other figure with a sword.
We must rise up!
The smaller figure grows larger that the elf. The elf attacks start to slow.
And defeat our enemies!
The now larger figure grows, and soon all that is seen is a hand, which simply flicks the elf. The shadows making up the elf disperse.

((Hey, I did some world building. Like, ummm... having the arrow fly towards us. And writing the OP. That counts for somehing, right? Jeez this is hard to type on a mobile device. So many typos that I had to go back and fix.))