where do brake lines go?

I have a 2004 GMC Envoy and my drivers side front brake line is broken but I can't seem to follow the line back very far. I can see some wet staining of fluid but that's it. Is there a plate or cover hiding the junction or connection underneath?

Any help is appreciated

thanks

No one has any idea on where the brake lines go? Is there a schematic I could be directed to? I've searched and am stumped....

Thanks....