When spies need to make sure their colleagues get a package or a signal without anyone else knowing, they leave a dead drop in a specific location and trust that another spy—ideally the one they need to communicate with—will retrieve the package. You don't have to be a spy to make use of dead drops though: they can be useful to safely leave a package for a friend, play a game with multiple friends, or leave yourself something you want to retrieve when the time is right. More »
