Three level wiring help

Hoping someone might be able to help me with a strange wiring setup I have.

I can seem to find how or where my second story open/close sensors wired.

I have a three level home, two stories plus a basement. The main alarm hub is in the basement and all the sensor wiring from the basement and first story is ran to this hub. All of the second story windows have open/closed sensors but I can't find where these wires are ran to. I have one 4-wire labeled "upstairs" that comes into the basement and that is all. 

Is it possible there is some other module in my attic or in the wall somewhere? 

Could this 4-wire be all the upstairs sensors wired in series making one zone?

Any ideas on where to look or find my upstairs sensor wiring? 

I had 3 ‘Zone Expansion’ modules in my system. They all looped together and made a single connection back to the main board. If you had these, there’s no telling where they will be hiding. Assuming they are not in the control box to being with? Mine were all in one location. Looks like Ademco called them Remote Point Monitors. I had four of them. Adding zones 10/11, 12/13, 14/15 & 16/17.

No not in the control box, just the one 4-wire labeled "upstairs"

I am guessing if one of these "zone expansion modules" is out there I am out of luck on with the upstairs sensors unless I find it. 

I would agree. You need to find where they converge at least - then maybe extend them individually? Or maybe another Konnected board at that location assuming you can get power and wifi to it?

Buy or borrow a wire tracer, often called a fox and hound.  Commonly used in the IT telephone and business to trace cables. The "Fox" s a small signal generator that is connected to a wire to impose a signal on it. The "Hound" has a receiver that will pick up the signal on the wire from a foot or so away. Start where the existing wire dissappears into the wall. Put the hound against the wall and make a circle around the wire to determine what direction it goes from there.  Now the hunt is on. If you lose the signal start sweeping walls and floors until you find it again.  Good luck!