Variant word ladder. Each step down one letter changes OR is added or removed. A letter MIGHT be removed from or added to the middle of a word. For two examples, CORN —> CON or MAN —> MAIN
NINE and the niners? Nope
GINO and the niners? Nope
NONO and the niners? Nope
NIRO and the niners? Nope
Got there eventually. Combinatorics for the win! Thankfully the search space was only 4x25-1=99 options (might use that fact in a crossnumber).