When I got up this morning, my phones have no dial tone.

The first thing I did was look for a phone off the hook.
Then I went out to the NID, and plugged a phone into it. Works fine.
So the problem is somewhere in the wiring.

I checked the wiring at the terminals. Everything is good, solid
connections.

I went around to every jack in the house and plugged in a phone.
Nothing.

I'm at a loss. I expected to find a loose wire in the NID, but now I
don't know how to proceed.