Vox Populi Forum
They had to segregate both realities and be careful to not reveal if one (or either) were real.
In the reality where his wife is alive, his shirts are pressed. In the reality where the son is alive, not so much.
Different cop partners in both (the kid from "That Seventies Show" and the guy from "The Practice" ... both excellent.)
Two different psychiatrists (Worf and BD Wong) both insisting the other guy is a fake.
Of course, as a cop show, he has to solve crimes. Details of the crime in one reality leak into the other. He know which door to open because in the other reality, the crime is on "Blue Door" street.
Of course, the accident that started it all is not an accident (or so your mind would insist).
The cliff hanger at the end is interesting and suggested more brain bending to follow.
Perhaps one of the most sad and profound comments on the human condition (in the first episode). The wife (in the wife reality) rails on him because he isn't suffering like her because in his universe, he gets to see the son while she is left in a reality without her child. Yet, she must insist that the other world is a delusion.
In the final moments of the first episode they are laying in bad soon to drift off and she asks if he'll see their son tonight ... to which ... he replies Yes. Tell him I love him and the episode closes.
Our situation demands we buy into the madness. And, so, we do.