When designing a PCB, the signal routing and its return are critical to the circuit working properly. Great care is usually given to routing the signals, but often the return portion is the last thing considered, or sometimes it is forgotten altogether. This presentation will talk about the importance of designing that return path, with a discussion of the physics involved, where the energy flows, the interference caused when it is not controlled, and the planes and stackup needed. Additionally, we will discuss the best ways to contain energy fields, the spacing that helps prevent problems, and the routing and return movement from layer to layer. Throughout, we will discuss some signal routes and look at the paths that might set up the best possibility for a clean return.