Dusk in Cambridge. Above the jumble of ancient church spires and modern concrete monstrosities, the sun begins to dim and slowly sinks from view, swallowed by the desolate fenland to make way for the heavy cloak of night. And with the dark comes the quiet. The market stalls are long gone, lectures are finished and people only go out on the street to travel home or to unseen assignations. They chatter, but hurry to more comfortable surroundings in the cool autumn air.

Their movements are inconsequential to the lone figure who sits. And waits. High above the street in the tallest room in Corpus Christi College she sits and surveys the street and courts of her own college, occasionally gazing towards the proud medieval stonework of King’s College Chapel.

Darkness is her friend. As she looks out, the sky changes from blue, to indigo, to inky black. Figures are less frequent in the street now, and instead appear in the yellow squares which puncture the walls of the aged college buildings. A floppy haired man washing up; an exasperated girl gesticulating at her computer; an ebullient reverend on the telephone. She sees them all, but none see her. No one thinks to look up.

A stillness settles over the city as the church bells mark the hours. Gradually the yellow squares disappear into the darkness, until only one window remains lit by a dark red glow visible behind curtains. But even this is eventually extinguished, and as the last nervous fresher scuttles from a late night library session to their room, the college falls asleep.

Only then the figure moves.

Reaching under her bed, she draws out a long black case and pops the catches. Delicately she removes several tubes and lumps of dull metal and begins assembling them into a Shaher sniper rifle, freshly imported from Iran. Almost caressingly she clips into place her laser range finder and silencer before resting the weapon, carefully, on the window sill. She lines up her sights into Old Court and as her fingers curl around the trigger her eyes are inexplicably drawn to King’s Chapel again. Some day I will explore your hidden recesses, she seems to think, but not today.

She fires.

A titanium dart flashes from the muzzle through the rooftops and embeds its nose into the wall next to an Old Court window with a muffled thud. The figure was glad of that resident’s unusual red lightbulb choice: having a landmark to aim for had made planning easier.

Behind the dart hangs sixty metres of high tensile steel cable. The figure makes sure this is taught before clipping the spool to a metal peg beside the window. She is ready. With rifle safely strapped to her back she slips her legs over the window sill and gingerly stretches for the ledge five feet below her before dropping down. The cable leading off her windowsill is now at head height; she clips another wire onto the cable from a small pack around her belt. She pushes off the ledge.

Had anyone been looking up in Old Court, they would have seen a slender girl zipping down a wire, her black clothes barely noticeable against the starless sky. She lands feet first against the wall, knees bent to minimise the impact, and clambers up a foot onto the roof. She pauses, but there is nothing. Her descent has been silent, and no one is around to see her. Neither is CCTV a problem – English Heritage would never allow a camera system and all its miles of cabling to be installed in 14^th Century walls.

Carefully the figure works the titanium dart out of the wall. This area of roof is littered by metal bolts and pins, remnants of scaffolding and repairs. She selects one and threads the steel wire through it, tugging sharply to remotely deactivate the break which stopped the cable spool from coming loose as she travelled down. She loads the dart again, lines up her sights and fires, loose cable trailing across the court to the opposite roof.

Again the figure slides across, suspended by her waist. However, this time she doesn’t climb onto the roof. Instead she balances herself against the wall and attaches a black rubber sucker to a large window. A diamond cutter. She slices a hole, reaches inside, pushes a catch, and she’s in. It’s too easy to use the gear system on her belt to lower her down the wire through the opening.

Corpus College’s kitchens. She has to move faster, there is CCTV here. With luck the porter will be on his break, or at least not keeping a close eye on the kitchens, but better safe than sorry. The narrow beam of a flashlight helps her pick her way swiftly across the tiled floor to the very back of the room.

The first freezer is useless – full of meat for tomorrow’s dinner. The second is not much better. But the third is exactly what she came for…but so many options…

She makes a split second decision and grabs three boxes of Carte d’Or ice cream and stuffs them into the small bag between her shoulders. The deed done, there is no need to hang around now, relaxing could lead to capture. She jogs back across the kitchen, padded shoes making only the slightest of noises. She reattaches the wire trailing down the window to her belt, and pushes a small button. The powerful mechanism takes her weight as she climbs up to the open window and to the roof.

Again the figure pushes off, and again she lands on the other side of Old Court. Two sharp tugs loosen the dart and retract the cable to her side, and she catches the dart through one of the metal loops in the roof. Secure enough for her to make an ascent back to her tower, but not so firm that the dart cannot be retracted. Some of the stonemasonry may come with it, but that’s a risk that can’t be avoided.

The clip from belt to cable is reattached. But instead of carefully lowering herself off the roof, she takes a run up and dives –

Caught by her wires she hangs spread-eagle in the dead space above Old Court. She allows herself a small smile as she dangles, buffeted by a slight breeze. It’s just as fun as she’d imagined when she planned the caper – not that anyone could know, of course.

She lingers for a moment to enjoy her unique vantage point over the aged stonework and less aged weeds growing on it. But not too long. With a slight sigh she presses the button on her belt and the gears grind into action, slowly winching her up the incline to her tower.

Very slowly. She’d be bored by the inching speed if it wasn’t for the view of windows rooftops and small carvings people don’t see – certainly not from this angle. But something can’t be right, her ascent is slowing down!

The night is suddenly very, very quiet. The little humming of her electric motor has stopped. And so has she.

Suspended on the perimeter of Old Court, she is stuck, still a third of the wire to climb, and the nearest rooftop just out of reach. She feels a lump of panic rise in her throat but pushes it away. It isn’t in her nature to be put off by a slight set back like this!

She begins gently swinging back and forth, hoping to create enough momentum to restart the motor. All the while she strains her hearing, waiting for that buzz of motor to signal she can stop.

She focuses so much she doesn’t hear the footsteps until they stop.

The figure breezes and catches her breath in her throat. Carefully she looks down. There’s a porter directly below her, scanning Old Court with a torch.

Has he seen her? No, he’s got no idea. No idea that a simple upwards glance, or chance reflection from her wire would give the whole game away. He must just be on his rounds – if he knew about the kitchens he’d have gone straight there and raised the alarm, surely?

Even if he doesn’t know, it’s a precarious position. She hasn’t time to wait for him to move – ice cream melts, after all. As silently as she can, she starts swinging. She keeps an eye on the porter. He’s scanning the walls of the court. She feels the tiny motor at her waist start to jerk…as soon as it starts he’ll hear the buzz! Now she realises she’s got to wait for him to go before she can –

An explosive sneeze from the street ricochets around the court, drowning out the renewed hum of the motor. The figure is suddenly moving again, higher and faster. By the time silence returns she is well out of earshot of the porter. She can’t believe her luck! The loud noise seems to have snapped the porter out of his reverie, as he shakes his head slightly at a secret thought and walks away towards the hall.

By the time he glances back for a last look at the court, she’s swinging over the window ledge and unclipping her belt wire, safe back in her tower. She stows away her booty, and then there’s just one last thing to do, although covering her tracks isn’t going to be a quiet matter. Unhooking the cable break from under the window, she pulls with all her might. The cable slackens slightly. She pulls again, and with a groan the titanium dart wrenches out of the 14^th century stonework, flying backwards across the court. It zooms up towards the figure, spooled back like a tape measure. She’s finished.

Alarmed by the crash, the porter rushes back into the court. He stops, takes on look at the lump of stone on the cobbles and sighs. Bloody maintenance department can’t keep the old place together!

He glances around, but he can’t see a culprit – she’s already tucked up safely in bed.

*                                             *                                             *

The following evening, three girls are sat around a laptop in New Court. One of them clatters around with bowls and spoons. “That thing in the kitchens is an odd one, isn’t it?” She says.

“Yeah,” says another, “the porters have been going through all the student kitchens today.”

The first girl looks puzzled. “Well they think it’s someone from college,” explains the second girl. “Why would someone from outside break into just the kitchens and nick ice cream?”

“Ah, I see,” says the first. “Anyway, this talk is making me hungry. It was good of you to get us a box for Downton time before all this kicked up. I don’t know how you kept it from the porters’ searches! Scoop?” She looks at the third girl who leans back on the sofa, smiling.

The girl knew the porters wouldn’t find their missing ice cream in a student fridge – why put it there when she’d found a space under her tower floorboards and lined it with insulator? They’d never know, and neither would her friends.

Victory is sweet, she thought, as she tucked in.