Here is a video of Physicist David Morgan explaining a tesseract (4-D Hypercube) in a tribute the late Madeleine L'Engle.  I give nearly the same exact speech every time someone sees the stained glass hypercube on my desk at work, including today in fact.  Also, the video starts with a Hypercube projection that looks a lot like one rendered using my 4-D POV-RAY rendering technique.