3-way switch in stairwell

[Treehouse2339]

I cant believe I am stuck with this.  I have a U-shaped staircase with a fixture in the ceiling of the second floor over the landing.  How do I have a switch at the bottom floor and the second floor that both control that fixture?  The fixture is on the second floor plan so when I am on the first floor, I cant see the fixture to drag a switch leg.