The Mathematical Bridge

by Jim Kelly

  In summer the journey would have required him to use his weight on the pole, like a lever grounded in the gravel bed, to propel himself forward, but tonight the Cam was a torrent and so the river took him on at speed, and ahead he saw quite distinctly the white water of the approaching weir, to one side of the sluices and the lock.

  His torchlight swept the flood, left to right, left to right. The river was black but threaded with whirling circles of silver bubbles. On the distant lock bridge, the keeper worked at an iron wheel, inching the sluice gates shut. A police constable, on the far bank, trained a torch on the water as it gushed through the narrowing gap, watching for the child.

  The snowfall faltered; the moon appeared through a break in unseen clouds, shining over the wide, bubbling stream. The punt raced onwards, so that Brooke had to cling to the sides. His eyes scanned the water and, for a second, he almost missed it, something not moving with the flood: a glimpse of hessian; a hand, seeming to reach up, breaking the surface twenty yards ahead. In three tumbling seconds he was almost upon it, reaching out, knowing even in the moment that he was a yard short. In an effort to lock fingers to fingers he nearly tumbled out of the boat. Then he looked back, levelling the torch beam, but the hand was gone.

  The punt dipped, swung and plummeted though the narrowing gates of the sluice. To the right he glimpsed the lock-keeper’s face, shiny with sweat, a hand raised, the eyes wide. Below the lock the cascading flood created a whirlpool, which spun the punt, with Brooke at its centre. Only now, slipping away from the lock, did he notice the thunder of the water as it diminished, leaving a strange, trickling calm. The lock was shut behind him. Had the child slipped through, or was he trapped in the river above?

  ‘Any sign?’ shouted the lock-keeper, a silhouette against the searchlight.

  Brooke strained to catch the echo of a child’s voice, but all he heard was the strange Brrrr! Brrrr! of a distant nighthawk in the reeds. He swung the torch across the water’s surface.

  ‘Nothing,’ he said, in a whisper to himself.

  CHAPTER THREE

  Brooke deployed the meagre resources of the Borough to their limit. One radio car was sent to Baits Bite, the next lock downstream, to make sure its sluices were shut too and that they stayed shut, while preparations were made to dredge the whole river at dawn, down from the Mathematical Bridge. Where to concentrate the search? It was probable the child had been swept through the sluice into the lower river with Brooke and the punt, although the locks had been closing, and he might have been caught in the spiralling currents and swept into a side water, a backwater or a ditch.

  The Borough’s night watch of six constables were set, three on either bank, to walk the mile from the Great Bridge to Baits Bite. The army’s motorised river patrol boat was allocated the upper river. A mobile searchlight from an ack-ack gun emplacement at Marshall’s airfield was trundled into place on the bank. After the white water fall between the sluice gates, the surface here was alive with bubbles, whirlpools and flotsam – twigs and branches, moss and reeds. Lights blazed in the riverside narrowboats and houseboats, their owners on deck, keeping watch. The WRVS, alerted to the emergency, had arrived with a mobile tea van at the lock gates.

  With each quarter-hour chime of the city clocks, hope faded.

  Brooke set up a command post of sorts in the lock-keeper’s cottage. While its exterior might be charming, its interior was utilitarian, the decoration strictly limited to the green and white livery of the Cam Conservators, the ancient custodians of the river, according to a brass plaque over the door. The front rooms were used to store spare ironwork for the locks, dredging hooks and large drums of lubricant oil for the sluices and gates. The lock-keeper, a widower, seemed to inhabit only a small rear kitchen with a cot bed and a pot-belly stove. But he did have a phone, a wall-mounted Bakelite model with a printed card fixed to one side listing numbers for the locks up and down the river.

  Brooke set in motion plans for the day shift to continue the search. The unsaid question was implicit: the search for what? Not a child any more, but a body. There was little doubt the boy – the voice had been high, but definitely a boy, according to the porter – now lay on the riverbed, his lungs flooded with river water. It wasn’t just a search for a corpse – the victim’s identity would be a clue of itself. There might be more: wounds inflicted, clothes, the drawstring, the sack.

  Brooke studied the lock-keeper’s chart under a bare light bulb. He’d swapped the ochre-tinted glasses for the green to reduce the painful brightness of the electric light.

  The chart showed the Cam, rising in the southern hills, curling around the city, before heading north to the Fens. The child had been thrown in the river – where? The answer had to be upriver of the Mathematical Bridge. Small tributaries – the upper Cam, the Granta, the Rhee – formed a network of streams and pools. How long could the child have stayed afloat before passing beneath the Mathematical Bridge? A few hundred yards, half a mile? By daylight the Borough’s radio cars would be assigned to bridges and villages upstream, just beyond the leafy suburbs of interwar semis, where house-to-house enquiries could begin. Had anyone heard a child’s cries? Had anyone lost a child?

  The map’s filigree channels of river and stream, dyke and drain, began to swim before Brooke’s damaged eyes. Exhausted, he needed to find a place to rest. The best cure now for the pain was a walk beneath the cold stars, the darkness a salve. And he didn’t have to keep his own company, for the city was full of nighthawks, ready with a fireside, or tea, or whisky, and often advice, when a case proved intractable. Or even a couch, or an armchair, if sleep did fall as it often did, without warning, like a hammer blow.

  So he abandoned the lock-keeper’s cottage and set off back into town. Parker’s Piece – the city’s great open park – was a ghostly encampment of white bell tents, an army camp since the first week of the war. A few fires burned in the gaps between the tents. With a jolt the scene reminded him of a night in 1934, when he’d been a detective sergeant, shadowing the hunger marchers from Jarrow. The ragged, jobless men had reached the city bounds at dusk. They’d been met with tea and buns at Girton College but with the stern indifference of the Borough when they got to Parker’s Piece. The sense in which his duty, and his sympathy, had pulled in opposite directions had left him wary of demonstrations ever since.

  But here, in a military camp, he felt at ease. Claire always said he cut a determined figure: hat; broad shoulders, narrowing down to the feet, which seemed to coalesce at a single point, like a nail driven into the ground. A corporal in fatigues appeared with a torch and checked his warrant card, waving him on with a warning to tread carefully.

  In five minutes, he reached the distant iron gates of Fenner’s cricket ground. The university’s pitch was untroubled by a single human footprint, although the spectral wings of birds, caught at the moment of take-off, dotted the outfield. A short street of large suburban houses led away into a cul-de-sac. The green door of the last house was always on the latch, so he opened it carefully and climbed two sets of stairs to a bedroom.

  Detective Chief Inspector Frank Edwardes lay in his deathbed, propped up on a series of pillows, his grey marble skin catching the light of a candle set by a pile of books. The window, ajar to the frosty night air, gave a view of the ghostly cricket field. The moon, now that the clouds were clearing, cast a cold light, creating shadows of the leafless elms which circled the ground.

  ‘Eden,’ said Edwardes, suddenly opening his eyes.

  They heard footsteps on the floor below. ‘That’ll be Kat making you tea.’

  ‘I’ve woken her,’ said Brooke.

  ‘I doubt that.’

  Kat, Edwardes’ wife, was a nurse who’d worked with Claire and now cared for her husband.

  ‘Any news from the river?’ asked Edwardes.

  Beside the bed, against one entire wall of the large bedroom, was a bank of radios. In peacetime, Edwardes had been a ‘ham’ – an amateur radio enthusiast – one of tho
usands across the country building simple transmitters, running networks, tracking exotic messages from Europe and beyond. War had brought a prohibition on all radios, which had to be handed in to what they were all learning to refer to as ‘the authorities’. There was one broad exception: any ham who agreed to monitor the airwaves for useful data, and send it promptly to the intelligence services, could keep their kit.

  Edwardes tracked the Borough’s radio car transmissions along with the rest of the nightly ‘traffic’.

  ‘No news,’ said Brooke. ‘There’s no sign. I saw his hand, Frank. Nearly got him, but the current’s too strong, and the lock gates were open.’

  ‘Well done,’ said Edwardes.

  ‘For what?’

  ‘For not jumping in, Eden. No one likes a reckless hero. We all know you swim in the river. But not in the dark, not in freezing water, not in a flood – you had no chance.’

  Brooke nodded in agreement. ‘You’re right. Too cold, Frank. Even for me. And the boy was gone in a moment. There’s ice now, great plates of it. Any colder, any longer, and the students will be out on skates.’

  Edwardes lit a cigarette and threw his head back. ‘I’d like to see that again. That’s how I met Kat. Last winter before the Great War, out at Coe Fen. I fell over, she picked me up.’ His eyes fixed on the middle distance.

  Returning from the sanatorium in 1919, Brooke had abandoned his studies at Michaelhouse to join the Borough, the damage to his eyes making extensive reading and laboratory research impossible. His father, a distant figure, had won a Nobel Prize for developing a serum for diphtheria, a breakthrough which had saved thousands of lives, possibly millions. Brooke, a hero of the war, still felt the need to carve out a sense of purpose from the peace. The police force had offered a chance to solve logical problems and serve the city he’d adopted as a lonely child.

  Edwardes had been his mentor. They’d worked together for nearly twenty years, from war to war, policing the city in the age of the dole queue. Nine months ago, an unspecified canker had struck the old man down. Brooke now had his superior’s office, and would have had the rank, but he’d been in no hurry to step into a dying man’s shoes. The fiction that Edwardes would return, cured and in fine health, had been carefully maintained. His life would end in this room, and possibly before the first ball was bowled on Fenner’s in the spring.

  A burst of Morse code filled the room and Edwardes took up a pad, effortlessly jotting down lines of apparently random letters in groups of five.

  When silence fell, he studied the note, then laughed. ‘Not even in code,’ he said. ‘One of ours. It’s always one of ours. A ham out at Royston. He says he’s just picked up a message from Felixstowe that the sirens have sounded. Perhaps this is it at last, Eden. The real war.’

  Brooke took the armchair as Edwardes began to describe the latest news from the BBC: fears over a German invasion of Norway, troop movements near the French border. His voice seemed to fade away, and when Brooke closed his eyes he tumbled backwards into a sudden sleep.

  When he woke, twenty minutes later, Edwardes was reading. A cup of cold tea stood on the table beside Brooke.

  Edwardes closed his book. ‘Tell me more about the child in the river.’

  ‘Porter at Queens’ heard a voice cry out “Help me!” Just that. Swept past under the Mathematical Bridge in a sack. I’d guess he’d be four or five years old. A boy. There’s no hope, but it would be nice if there was justice. The problem is I can’t visualise the killer. Who could do such a thing?’

  ‘You’re right. It’s beyond understanding. That’s your problem – he’s the bogeyman, this killer of yours. He comes with a sack to take away naughty children, Santa Claus in reverse. A sack of toys for the good children, just a sack for the bad. If you think it through it says a lot. I’d focus on why, not who. The modus operandi is stark. You don’t just have a sack to hand. So, premeditation. And it’s ruthless, and pitiless, so I’d say it was professional. It’s not a domestic, is it? Where did he chuck him in?’

  Brooke started to visualise the bridges upstream of the Mathematical Bridge: Silver Street, the Little Bridges, Fen Causeway …

  The old man set down his pad with its scrawl of dots and dashes. ‘You’re not wandering round Cambridge with a child wriggling in a sack – are you?’ said Edwardes. ‘It’ll be a car, or a truck, with the kid in the back, probably unconscious. So he stops, slings the sack over the parapet and drives off. The icy water brings the boy round.’

  ‘God. What a thought.’

  Edwardes sat up. ‘I’ll tell you this, Eden. Odds on he’s killed before. And you’ll know what that means. It’s a cliché, but it’s a brutal truth: if he has to, he’ll kill again.’

  CHAPTER FOUR

  At the Spinning House, Brooke slept for an hour in cell six, a stub of candle on a wooden ledge, the darkness like velvet lying on his eyes. Waking, he felt hungry. Claire worked the night shift at the city hospital and when they could they met for breakfast. Brooke shrugged himself back into his Great War trench coat, grabbed his hat and climbed the spiral metal staircase up to the Spinning House’s duty desk, where the sergeant reported no news from the river, except that the dredging was about to begin and that the banks had been thoroughly searched.

  Brooke stepped out into Regent Street, the old Roman road which ran like an arrow into the city from the low chalk hills of Gog and Magog. The scene was utterly still. Dawn was in the eastern sky. He felt the familiar childhood thrill of having the city to himself, a plaything, a puzzle, a labyrinth. Opposite the police station stood the frontage of the Cambridge Daily News, where a single light shone at an upstairs office, and Brooke heard a telephone ringing unanswered. Next to the News stood the New Theatre, a dramatic confection of balconies and ironwork. Theatres had been reopened, along with cinemas, and he and Claire had got the last seats in the house the week before to see Gaslight. Brooke thought that was a luxury: a nice, neat murder, all tied up in one small house.

  He set out for Addenbrooke’s Hospital, a half-mile, weaving through the university’s science district, a grid of cool, antiseptic brick blocks. He came out opposite the pillared splendour of the Fitzwilliam Museum, with its four sitting lions, which he’d climbed aboard as a child, until an irate curator had dragged him off. Opposite, he turned into the iron gates of the hospital, and looking up saw slivers of light where the blackout blinds had failed. Dawn was rising, casting gold on the steam and smoke billowing from chimneys and pipes.

  Once inside, the corridors, glassy and lit, led Brooke to Admissions, his metal Blakeys sounding like gunfire on the polished lino. As he was in the building he felt standard procedure could not be ignored, so he tracked down the sister and told her about events on the river. Had anyone suspicious been seen overnight? They’d treated three cases after nine o’clock: two men who’d fought in the street outside The Eagle and inflicted identical cuts on each other with identical bottles, and an emergency appendectomy. Brooke asked if the Spinning House could be alerted to any admissions of children or victims of domestic violence. Was that the root of the crime, a family at war?

  Brooke ran up the stairs to Sunshine Ward. The children were being woken up for breakfast. They lay in thirty iron bedsteads down each side of the long ward, a few feet apart. There was a drifting aroma of stewed tea and burnt toast, and somewhere a radio played the Home Service, a piece of dance band music. The sun, on cue, was beginning to stream in through the windows down one side.

  ‘You’re not supposed to be in here,’ said his wife, smiling, standing in front of him, holding a bedpan in the crook of her arm. Claire was the sister on the ward, having transferred from Geriatrics. Children were going to be part of their lives again in more ways than one; their daughter, Joy, a nurse herself, was pregnant and now at home after six months administering last-minute health checks on soldiers bound for France from the dockside at Portsmouth. The year promised a grandchild.

  At the sanatorium outside Scarborough, where Brooke
had been sent after his ordeal in the desert, Claire had often touched him, pulling his hands away from his wounded eyes, or rubbing liniment into his shattered knee, where his captors had put a bullet in the hope he’d have to die, slowly, in the sun, when they’d abandoned him south of Gaza.

  He wanted to touch her now, but the bedpan was between them.

  ‘It’s an official call. I’m a detective inspector, Sister Brooke.’

  He took off his hat, running a hand through the thick black hair, pushing it back off his forehead.

  ‘That means you get a free cup of tea.’

  The sister’s desk was at the far end, with a view back down the serried ranks. This was Claire’s kingdom. She’d grown up the eldest child, with five younger brothers, and so her life often seemed like an endless, efficient attempt to bring order to chaos.

  While she issued orders to a staff of three nurses, Brooke noted the disturbing anomaly that was silent children. A few ate their toast and drank tea, others lay still, a drip above one, another being spoon-fed. The soft, church-like hush was unnerving.

  Brooke perched his hat on his knee; the injured knee, in fact, which had been rehabilitated through a rigorous programme of swimming initially administered by Claire in a pool at the sanatorium, the germ of his night-time summer passion.

  He lit a cigarette. ‘Last night someone threw a child into the river in a sack. A boy, alive. The porter at Queens’ heard a cry as the body went past. We did our best, although I’m pretty certain it wasn’t good enough. I’ve had the sluices closed and we’re dredging the lower river. I’ve mentioned it downstairs, and apparently there was nothing suspicious overnight. Nothing here? Any recent admissions? Domestic bust-ups?’

  Claire sat back, her blonde bobbed hair falling neatly into place. She had a round face crowded with large features, wide brown eyes and a generous mouth. Brooke doubted that any of the nurses had ever seen her discomposed.