I want to connect the wiring from my shed into a junction box on the ceiling in the basement. I opened the box to see what I was dealing with, I figured it should be simple, there is only 2 wires going in. but i am confused- black to black, and both white wires just loose on their own. How do I connect my new wire into this box?

Thanks

I want to connect the wiring from my shed into a junction box on the ceiling in the basement. I opened the box to see what I was dealing with, I figured it should be simple, there is only 2 wires going in. but i am confused- black to black, and both white wires just loose on their own. How do I connect my new wire into this box?