How would I go about doing this?

Hi I have a question. I am working on a game and basically for the end of the map I am trying to get that "Assassins Creed" type of style. I glowing grid that you cannot pass. Do you know what I mean?
If you can, could you please give me a general idea about how I should go with this? Or if its even possible with Unity Free? I do not need a really detailed explanation since I wont be on this part till a month or so. Thanks!

Something kinda like this. But less of a 3d and more of a 2d wall. http://www.youtube.com/watch?v=mxadvTXzZZY&feature=related