She advanced in a creeping crouch, her knees bent, her thigh muscles and core strength tested by the weight of her equipment and the unnatural movement. Her body had recovered well from pregnancy and childbirth, however, and from the rigours of hunting and fighting in the huge, open mausoleum of New York last spring. Three months back home with Bret and Monique had helped with that. Three months in which she regained her strength, and bound it tightly with new layers of resolution, and a fierce will to lay her hands on the man she blamed for nearly destroying her family.

Bilal Hans Baumer. Al Banna.

Or whatever he was calling himself these days. In Manhattan he had been known as the Emir. Now he was ‘the target’. Her target. As he had been for a year before the old world had fallen.

The barrel of Caitlin’s 417 swept back and forth in a tight arc as she moved up the creek like some nightmare black arachnid. The burbling splash of the stream covered the sound of her boots. She took care to step where the flow of water would quickly erase any sign of her passage. Mosquitoes hovered around her in a cloud, drawn by the opportunity to feed, but thwarted at the last moment by the odourless insect repellent she wore. As the environment adapted to her presence, it also disguised her advance, enfolding her in the shrill, creaking chirrup of a billion insects, the shriek of bats and nocturnal birds of prey, the rustle of larger animals moving through the undergrowth, and once, as she ducked under the limb of a half-fallen tree, the dry hiss of a viper slithering languidly along.

Caitlin dropped a hand to the knife at her hip and, with one fluid motion, threw it at the snake, spearing it to the branch. While it was fixed in place, she crushed the skull with a swift stroke of the Heckler & Koch’s butt stock. Pythons didn’t worry her, but vipers were incredibly foul-tempered. Best not to take chances.

After forty minutes the Navman on her forearm began to vibrate ever so slightly, warning her that the stream was about to veer away from her intended heading. She slowed to a stop and took her time absorbing the signs . . . She listened for the slightest fluctuation in the wall of sound thrown up by the insects in her immediate vicinity, the splash of water across the creek-bed, slightly rockier here. Her eyes took in the noticeable brightening of the world in her goggles under a thinner canopy, as a strengthening breeze opened a hole in the silver-grey cloud cover to let moon and star light spill through.

But nothing human.