But it hadn’t hurt as much as she had expected. Maybe the quacks were right; maybe their new, “natural” chemotherapy regime really was a little less brutal.

And afterwards, they shared the post-coital cigarette they were both too old ever to give up — and what would be the point anyhow? — and then they sat up in bed, blankets around their bony shoulders.

And they pulled their computers to their laps and went back to work.

Alfred got online to the International Astronomical Union nets, and Monica skimmed through the latest entries to the electronic preprints library being maintained by the National Laboratory at Los Alamos.

The papers on string theory, since the Venus incident, had become a blizzard. The excitement seemed to crackle out of the screen at her.

But Alfred had found something new on the astronomy nets and was becoming excited too.

Now people had started looking — NASA had hastily thrown up a couple of new satellites — they were starting to find signatures like the Venus event’s all over the sky. Alfred tapped the screen to show her. “Like these. Gamma ray bursts. Called GRBs by those who study them. Flashes of energy, emanating from explosions that lasted a few seconds…”

Huge explosions, he told her. By some estimates, radiating more energy in a few seconds than the sun does in ten billion years. There were lots of candidate explanations, none of them particularly satisfactory. Maybe asteroids were crashing onto the surfaces of neutron stars. Maybe neutron stars were colliding. Maybe giant helium stars were imploding.

“Or maybe,” Alfred said feverishly, “some interstellar cousin of our Venus killer is at work…”

She found it hard to concentrate on what he was saying, given the buzz on the Los Alamos nets.

She tried to summarize for him what had been going on in the world of theoretical physics, galvanized as it was by the natural laboratory which Venus had somehow, magically, turned into. “Alfred, string theory is the best way we have to describe the kind of extremely high energy density events we’re encountering inside Venus…”

String theory was a candidate Theory of Everything — which, if successful, would be a simple theory whose corollaries would describe a universe that was unmistakeably ours: with quarks and electrons, gravity, nuclear forces and electromagnetism, three space dimensions and one of time, a universe of atoms and babies and stars.

“According to string theory,” Monica said, “the most elementary object in the universe is a loop of string. Unimaginably tiny. Ten to minus thirty-three centimetres… The string has different modes of vibration. Like a violin string. Each mode corresponds to a particle, a quark or an electron. And the laws of physics correspond to harmonies between the strings” tones.”

“Ah.” He smiled. “The Universe as a symphony. Rather beautiful.”

“But,” she said, “there’s a complication. String theory only works in a ten-dimensional space-time.”

Alfred rolled his eyes. “I always hated theoreticians.”