Off Topic: Love blooms on the braid in This is How you Lose the Time War

"My most insidious Blue."

Red writes to Blue. She leaves her letter in a pot of boiling water in an MRI machine. Blue writes to Red. She leaves her letter in a spew of magma as Atlantis is destroyed. Slowly, it dawns on me that this is - what's the half-forgotten term? - an epistolary novel. A story in letters. Red and Blue, deadly agents from different sides in a hideous war, exchanging notes across the crackling divide.

And the war takes place in the sweep of time - all of time, and across a multiverse of different universes woven together into a braid. This is what the agents do: they zip back and forth through time and across dimensions, tweaking events so their side inches closer to victory. But then the notes - teasing and taunting at first, one brilliant agent recognising their opposite. And of course the teasing and taunting cannot last forever.