Interactive magazine fails (only a little)

The easiest way may be to have a persistent table of contents button on all pages.

Other than that, if you want to implement using the browser’s back/forward button you’d either need code to change the anchor tag (similar to the advice in this topic) or to use the javascript pushstate API. I glanced at the turn.js documentation and didn’t see any methods it provides to do this for you, so it’d need to be custom code.