Ajax Custom

I have a page set up on my old site that has a left column full of article headers, and a right column that fills with ajax content based on a click on one of those article headers.

I'm trying to figure out how to duplicate this functionality in Drupal. I've created a content type "article." It has a title, date, and text. So I've created a view for this content. I have one block listing out the article headers (for my left side). And another block for showing the title, date, and text in full.

I just don't know how to bring in a full article with ajax. Listing out the headers is easy. Listing out the articles is easy. But the ajax part is hard. I used to just have a file with a query string that the ajax would call. And then I would just get a pure text response from that page to load with ajax.

Where can I go to recreate such an effect?