“What has rivers with no water, forests but no trees and cities with no buildings?” It’s a riddle. I’ll give you the solution later in case you can’t solve it. When you read the answer, it will be so simple, you’ll wonder why you didn’t think of it.

We had a riddle at our house this week: a puzzlement, a conundrum we could not crack. But when at last we did, it was so simple we felt silly.

About ten days ago I heard a repetitive, mechanical beep in my office. It seemed to come from up above so I thought maybe it was the smoke alarm. It’s wired into the house current but it has a battery backup. We know because it was beeping when we moved in about ten months ago.

But the beep didn’t seem to be occurring regularly enough for a smoke alarm. I didn’t hear it for a long time and then it beeped while the central heat was on. I decided it could be a squeak from the air handler, which is in the attic of that room.

I told my hubby about it, thinking he might investigate, since that’s what he does for a living. But since that is what Dan does for a living, I guess he gets a little tired of looking at heat and air systems. It wasn’t bothering him and it went on unchecked.

Then one night, Dan was awakened by the beep. Our bedroom is two rooms away from my office but that silly squeak had ruined his midnight hours. When I got up, I found the battery-operated house phones were piled in my office chair and three doors closed between us and them. Whatever it was, he had determined it beeped every ten minutes, exactly, all night long.

Upon further investigation, we decided the beep was in his office, not mine. He could not tell if it was the smoke detector or his new computer. Dan climbed a ten-foot ladder to get close to the smoke alarm in this area. I stood on the other side of the room to be the direction detector.

On the ten-minute mark, a loud beep came from Dan’s desk. The smoke alarm light didn’t flash. It was the computer!

I opened the “hidden icons” to see if there might be a revealing message. It said something about installing a driver for a memory card. His machine is running Windows 8.1 with a touch screen so I’m at a loss to help much. I pointed this out and left Dan to deal with it.

Life got in the way and he simply turned the computer off. I went in the kitchen at the other end of our long house and Dan went outside.

“Beep!” went the powered down computer. I could not believe I was hearing it from 40 steps away! It sounded like it was in the room with me.

Hearing my report, my husband insisted it couldn’t be the computer. We unplugged the battery charger and pulled the batteries out of his atomic clock. We unplugged the battery back-up for the phone system. We checked every gadget that uses batteries. All our devices were deactivated and the beeping seemed to stop.

That night after we turned out the lights, had our goodnight tête–à–tête and got quiet, we heard one more loud beep from his office, which is right next to the bedroom.

Dan jumped up and turned on the light, mumbling something about the portable intercom system.

“There’s one on your desk,” I informed him.

“That’s it!” he said. He took the batteries out and our riddle was solved.

The Culprit

There is an intercom link in my office and in the kitchen. It’s no wonder (now) why we couldn’t figure out for sure which room it was in because it was in all three. We never read the instructions, or if we did, we forgot the system has a low-battery-warning beep. Just like a smoke alarm.

That’s how riddles are. When they’re solved, they’re too easy to be a problem at all.

So do you want to know what has rivers with no water, forests but no trees and cities with no buildings? The answer is so simple—it’s a map!