The squad leader, who was wearing a white ski mask that made him look like a pro wrestler (or a jack-o’-lantern snowman), crunched slowly across the pack ice to Mom.

“I am Colonel Dragunov, here to tell you that Minister Szymanowicz is not pleased,” he said menacingly through the mouth hole of his mask. “He sent you here to the North Pole to find stolen art masterpieces, not to take a joyride across the ice.”

“And why did he send you?” asked Mom, who, don’t forget, used to be a spy and didn’t threaten easily. “We only just arrived at the pole a few hours ago. We were out here on a scouting expedition. Getting the lay of the land. Looking for any unexpected storage structures.”

“That’s right,” I said. “The art thieves might’ve built themselves a frozen Fortress of Solitude out here somewhere. You ever heard of cold storage? Well, that’s what this would be. A subzero warehouse, filled with all sorts of treasures. Rembrandts, Picassos, those other guys…”

Dragunov squinted at me like I was an annoying narwhal. “Is this true?” he asked Mom. “Were you searching for this fortress of ice?”

“It is one possibility we are considering,” said Mom. “Definitely.”

“Here is something else for you to consider.” He reached into his chest pocket.

I flinched because I was half expecting him to pull out one of those gnarly survival knives with a sawtooth blade on top.

Instead, the Russian pulled out an envelope sealed with wax.

Another clue from the Enlightened Ones!

I noticed a small hole in the top of it as he handed it to Mom.

“This was found nailed to a wall of the Hermitage Museum in the blank spot where our revered Rembrandt used to hang. Minister Szymanowicz gave us the order to fly north and parachute over the North Pole to deliver it to you. Apparently, it is a very important document, da?”

“It could very well be,” said Mom.

She tore open the envelope.

“Is it a ransom note from the art thieves?” asked Colonel Dragunov.

Mom shook her head. “No. It’s another clue.”

“A clue about what?”

“Where your country’s lost treasures might be stored, along with priceless art objects and antiquities stolen from collections all around the globe!”

Dragunov leaned in close to Mom. He was twice her size. But you know what? Mom had had so much martial arts training, I think she could’ve taken the guy.

“Use this clue,” said the soldier. “Find our art. Do it fast. Because my boots are thin and my feet are cold!”

After checking out this fourth clue, I was positive about one thing.

We were freezing our butts off in the totally wrong spot.