Related Clues:

• The sixth and last letter?
• Two letters after delta
• Z, to a sorority pledge
• Greek letter that surprisingly isn't last
• Z as in Zografou
• Unknown projected delivery date for letter from abroad
• Z, in Athens
• Greek letter that one might expect to come last
• Letter that's only 25% of the way through the Greek alphabet, surprisingly
• Greek letter (but not the last one)
• Oscar winner Catherine __-Jones
• Captured in bronze, tallish Greek character
• Greek letter that sounds like it should be last, but isn't
• Greek character lost in maze, Tantalus