Create a property in your detailViewController, in my case it's webViewController.
@property (nonatomic, strong) NSString *urlString;
When your tableView cell is clicked, pass your plist string to your detailViewController, by setting this property. Sample code:
WebViewController *webViewController = [WebViewController new];
webViewController.urlString = urlString;
[self.navigationController pushViewController:webViewController animated:YES];
That's all, now your detailViewController knows this passed string.