Nroug7: A mixture of two substances if a solution, so if a door is a solution, what is the solution to and what needs to come after a solution?
Ok, you've got me interested now. Back to basics. If a door is a solution, and it is a mixture of two substances, it is an agreement. The solution is to the problem, that has not been stated. After the solution comes the implementation of the result.
This isn't the answer, but maybe someone can springboard from it.
adambiser: Are we allowed to guess multiple times? If not, kindly ignore this
Door = solution, house = a problem, stairs = taking action based on the solution; thereby making the solution useful
I think our noble quizmaster is keen for someone to get that epiphany and solve the puzzle (I always am in his position), so I think you're free to guess as much as you like.