Solution to Evan Birnholz’s July 4 Post Magazine crossword, “It’s a Start”

The parenthetical clues and the title should hopefully point you to the first aha moment of the puzzle: The first words of these theme answers are the first examples in their given categories. ALPHA is the first Greek letter, MERCURY is the first planet from the sun, ENSIGN is the first commissioned Navy officer rank, and so on. Using the single Roman numeral I may have been cheating a little, but it made me laugh when I thought of it. There’s no Roman numeral for zero, so it was a convenient example of a category whose first item starts with the letter I — and to perhaps prevent a little bit of confusion, I figured it would be best if there were no other Roman numerals in that answer, which is why I landed on I WON’T KEEP YOU.