1194, Sherwood Forest, Nottinghamshire

Moonlight illuminated the forest track in front of Bob. It was just possible to see the dark stains of congealed blood in places, the scuff marks of boots, the glint of several twisted and broken loops of chain mail, and the pale feathered fletching of a few arrows deeply embedded in the dirt.

Bob reined the horse in and stepped down on to the track.

It was silent except for the hiss of a breeze through the endlessly stirring trees and the far-off hooting of an owl. He examined the signs of battle more closely.

Heavy boots close together had rucked the dirt, and many small gouges in the mud suggested arrows that had embedded themselves in the ground and been retrieved later. Bob nodded with calm certainty that this was the site of the ambush that had happened over twenty-four hours earlier.

He wandered over to one side of the track, pushing aside the thick ferns and bracken that filled the forest floor between the stout oak trunks. He soon found the first body, hastily pulled out of sight and dumped amid a thick clump of nettles, stripped of anything of value and left as carrion. He picked his way along the edge of the track, finding several more bodies, all of them stripped of their mail and their leather boots and left with nothing but their leggings and blood-stained tunics.

Half a dozen bodies in total. He flipped the last of them over; to his relief, none of them was Liam.

Relief.

Bob queried his mind for greater clarification. His on-board hardware looked dispassionately at the impulses coming in from the organic nub of flesh that barely deserved the term ‘brain’. The tiny electrical impulses fired off by the rat-brain-sized organ conformed to a pattern that humans would call an emotion.

Yes. Relief.

He stood up and listened to the night, hoping that beyond the hiss of stirring branches he might hear the faint and distant cry of human voices raised in drunken celebration or calling for help. But he heard nothing. Just the owl.

Bob’s decision-tree had been here before. On his very first mission he’d lost Liam in the aftermath of a battle for the White House; Liam had been taken away in one of a column of prison trucks. His AI then had been woefully unprepared for the decisions it had to make. But he’d managed to do it. He’d managed to reprioritize the mission goals to put rescuing Liam at the very top. Technically, a breach of his programming, but also something he’d been proud of.

This time round, it was a far easier decision. This mission’s goals were so poorly defined and ambiguous that devoting what was left of the six-month mission envelope solely to finding his friend Liam was a nanosecond evaluation.

But how?

He could wait until dawn and attempt to identify a visual trail. A body of men moving through the thick undergrowth of Sherwood Forest would leave behind something that even an inexperienced tracker could follow.

He decided that was to be his plan of action, and settled down to a hunched-over squat amid some nettles to wait for the light of dawn. He wouldn’t sleep. Instead his mind would do what it always did when the rest of the world was in slumber: a defrag. A chance to play through the endless terabytes of data stored on his hard drive.

Memories.

To replay it all, every single image, every sound, every sensation, every smell. To try and make connections, to make associations, to understand a little better what it would be like to have a real brain. To be a real human, instead of an engineered tool … a meat robot.

He’d just started unpacking and sorting through a slideshow of memories when he detected the faintest odour of woodsmoke. Not the ever-present odour ingrained into the tunic he was wearing, the smell of melted tallow mixed with stale sweat. This was on the air … a fire burning somewhere out in the forest tonight, caught on the fresh breeze and carried for miles.

He sniffed loudly, his broad nostrils flexing like a horse’s.

The faint odour again.

He stood up quickly, scanning the woods in a steady 360° arc, hoping to detect just the faintest flicker of light deep in the woods. He saw nothing. But … he had the odour. Not just the smell of dry seasoned logs, but the vaguely minty odour of pine needles burning.

A campfire.

He decided to follow his nose.