In a world of near perpetual night that's illuminated only by an artificial sun, communications are only possible with the Letter Bees, elite couriers who must fight the monsters called Gaichuu to make their deliveries. Saved by a Letter Bee years ago after his mother was kidnapped, Lag Seeing finally gains employment at the Bee Hive but soon learns this job is even more lethal, as renegade humans now target Letter Bees. Fortunately Lag has the ability to see into the memories of others, and like all Bees he gets a Dingo, a partner to watch his back, but she's not what he expected her to be.
