Another Train Problem - The Peg + Cat Express. Albert Einstein's prize is missing! The clues point to everyone aboard the Peg + Cat Express. Primary Content: Deduction Secondary Content: Doubling.The Odd Sea -The Ocean / Odd Sea. Peg and Cat help the great Odysseus navigate the odd beasts and odd numbers of the Odd Sea. Primary Content: Odd and even numbers Secondary Content: Adding or subtracting 1 from an even number to get to an odd number.