We creators of fictional sleuths must never get so full of ourselves that we think we could actually solve a real-life mystery. But sometimes it’s hard to stay grounded. Take, for example, this recent snowstorm of clues that have led me to know what I’m getting for Christmas without even peeking in the box.

Here’s the backstory: It started some weeks ago when Carol went on a coat-buying spree. After several shopping trips, on-line purchases, take-backs and send-backs, she ended up with two coats, a brown microfiber jobbie with a hood for every day, and a beautiful plum-colored wool one for better occasions.

Clue One: During this coat-buying spree I remarked that I needed a new topcoat. “My old one has somehow shrunk two sizes,” I said.

She was surprisingly empathetic. “Only two sizes?”

A little more backstory: We get both our phone and TV through our Time/Warner cable. A couple of weeks ago Time/Warner started providing TV screen caller ID. When someone calls, their name and number appears right on the TV screen – a very handy bit of high-tech magic for a sofa slug like me.

Clue Two: The other night when the phone rang, Carol rushed out of the living room to answer it. Because she was not aware of the new TV caller ID service, she did not know that “Tom, Joseph A. Banks” and a phone number had appeared right above Wolf Blitzer’s head.

Clue Three: Last spring I bought a new sports coat at Joseph A. Banks. It’s a rather pricey men’s store for a writer, but they are always having sales. Apparently Carol had remembered my hint and was getting me that new topcoat I wanted for Christmas. How nice!

Anyway, when Carol returned to the living room, I asked, “How’s Tom?”

“Tom?” she squeaked, like a mouse that had swallowed an entire slice of Velveeta.

“Yes,” said I, “Tom from Joseph A. Banks.”

She began gasping for air like a guppy. (Actually she didn’t but, hey, I’m a mystery writer). I told her about the new TV screen caller ID. I began to sing “I know what I’m getting for Christmas” in that na-na, na na-nahhhhhh melody bratty kids use right before they get popped in the snoot.

Well, what could Carol do but confess? “You caught me,” she said. “Tom and I are having an affair.”

I didn’t believe that for a minute. I’d seen the guys who work at Joseph A. Banks. “Enough of your lies, woman! You’re getting me a topcoat! Admit it!”

That same night, my daughter, Jen, called and asked if I could watch my grandson, Gabriel, that coming Tuesday. Charley was going to be out of town and she had to work late. “Will there be pizza?” I asked.

Clue Four: The next night, while camped out in front of the TV to discover what other retail clerks my wife might be canoodling with, I could hear her talking on the phone with Jen. I heard them make lunch plans for Friday. I heard vague references to a box.

Clue Five: On Tuesday I drove to Jen’s to watch Gabriel. There was pizza, as promised. There was also a UPS box from Joseph A. Banks. A box big enough to hold a thousand lies. When I got home I mentioned seeing the box to Carol. “I’m not surprised,” she said. “Jen always shops there for Charley.”

Clue Six: Saturday morning I did the grocery shopping. I pushed my loaded cart to the back of the car and popped the trunk. There was that box from Joseph A. Banks. When I got home I mentioned it to Carol. “Somehow when you and Jen went to lunch yesterday, that box for Charley wound up in our trunk.”

“We’re hiding it here,” she said. Guilt was flooding down here face like that watery white gunk that pours off my brushes when I clean them in the stationary tubs after a day of painting kitchen cabinets. (Eat your heart out over that one Mickey Spillane.)

Clue Seven: After putting the groceries away, we headed out in the blowing snow to visit my mother at the rehab center. When we pulled into the parking lot, Carol told me she needed to get in the trunk for a minute. “With that big box of Charley’s in there, I doubt if there’s room for you,” I said.

“Just open the trunk.”

I obediently punched the trunk button on my key. The trunk unlocked with a dull thoomp. I followed her to the back of the car, snowflakes the size of pancakes swirling around my head like flying saucers with broken gyroscopes.

She grabbed the key from me and used it to slice open the box. She explained her insanity: “Jen was looking at the Joseph A. Banks website this morning and she thinks she saw the very thing she bought Charley at a better price than she paid when she ordered it through the store. She wants me to check.”

“We have to do this now?” We’re in an f-in’ blizzard here.”

Said my mendacious wife: “If the price on the packing slip is higher than the price on the Internet, we’re going to stop at Joseph A. Banks on the way home and see if we can get the lower price for her.’’ She pulled out the packing slip and checked it. After exploding with an expletive unfit for any holiday, let alone Christmas, she told me that the store had sent the wrong size! Now we were going to stop at Joseph A. Banks for sure — to see if we could exchange the wrong-sized Charley’s gift for the right-size Charley’s gift.

So on the way home we stopped at the mall, our tiny white Volkswagen Jetta slipping and sliding across the massive dark parking lot like a lost baby polar bear on an Artic ice shelf. Carol disappeared inside with the box. A half hour later when she came out, relief twinkling on her face like the 1,200 tiny Christmas lights strewn across our shrubs like so many frozen fireflies. She not only got the right size for Charley, she got the Internet price.

And that’s why I know I’m getting a topcoat for Christmas.

Then again, knowing how sneaky Carol is . . .