Just for clarity: the defender's word must follow Scrabble rules - that doesn't strictly mean it has to be found in a Scrabble dictionary, as many (particularly longer) words that are legal, are not in there
We split into two teams: red and blue. Each team has one "spymaster", and the rest of its players are "operatives".
(Sorry, I didn't come up with the theme.)
Everyone will see a 5x5 grid of words, representing people. Some of these words are "agents" for the red and blue teams, some are regular people, and one is the assassin.
The goal of the game is for your operatives to contact all your agents (guess all your team's words) before the other team does.