As a gamer, reading “What half-life measures in nuclear physics” and not thinking about Valve’s industry-changing shooter feels like sacrilege. This being said, knowing Half-Life is a great help if you’re trying to solve this clue.

Eight across clue. Screenshot by Dot Esports

• Hint one: Old teeth do this.
• Hint two: Decomposing.
• Hint three: The answer was an expansion pack for Half-Life.
• Hint four: Ends in “Y.”

I’ve had fun with this clue already, and we’re only just getting started—here’s the answer and why this is.