Among the ashes of a dying world, an agent called Red finds a letter marked "Burn before reading." So begins an unlikely correspondence between two rival operatives in a war that spans all of time and space. Red fights for the Agency, a post-human technological utopia; Blue serves Garden, a vast organic consciousness. Each travels up and down the threads of history, nudging events, toppling empires, and unmaking futures to secure victory for their side.
What starts as taunting between enemies, letters hidden in lava flows, tea leaves, and the rings of trees, slowly becomes something else: admiration, longing, and finally a love that neither side's future can permit. As their correspondence deepens, Red and Blue begin to work not for their masters but around them, and discovery means death. Caught between loyalty and desire, each must decide what they are willing to sacrifice, and whether there is any version of the future with room in it for both of them.
