This one takes a bit more observation than usual to appreciate, even on my part when looking at it later. Notice that all outer tribars actually share a center corner, that is the cube in the middle. There are also floating corners between the outer tribars that match them in a different axis than the closest join to the center tribar. It feels like I should point and talk at the same time for it to make sense :)
This constellation consists of four interwoven impossible tribars.