All 16 words, sorted alphabetically. Group them into four categories of four.
The four category names, easiest to hardest. No words revealed yet.
Theme name plus one word from each category.
ASTERISK, CATCH, CONDITION, and STRINGS all refer to hidden limitations, caveats, or qualifications — as in 'fine print' in a contract or offer.
ELPHABA (Wicked), GRINCH (Dr. Seuss), HULK (Marvel), and SHREK (DreamWorks) are all famous fictional characters with green skin.
CAPITOL (building), MALL (the National Mall itself), OBELISK (the Washington Monument), and POOL (the Reflecting Pool) are all features of the National Mall in D.C.
BRIDGE TROLL (fairy tales), MAD HATTER (Alice in Wonderland), RIDDLER (Batman), and SPHINX (Greek mythology) are all famous fictional or mythological characters known for posing riddles.