Michael and Janet are able to escape from the Judge to make their way to Earth, albeit with limited powers, to oversee the progress of the four humans directly. With those limited powers, Michael sees their main job as analogous to a snowplow: not to intervene directly, but to clear a path for the four to continue their time together which Michael sees as being the key. Being snowplows has unintended consequences which brings up the larger question for Michael and Janet of how much they can or should meddle in the lives of the four, as opposed to getting them together to figure things out for themselves.
—Huggo