‘From the church?’ asked Yaz. ‘Why not the hospital?’ But the couple ignored the question as they hurried out of the park, Johanna’s head lolling lifelessly.

  ‘All the others?’ repeated Graham. ‘What others?’

  The Doctor raised her eyebrows. ‘Looks like we’ll be taking a little detour on our way to Mr Einstein.’

  The four of them stood in the square in front of the cathedral and gazed up.

  ‘Whoa,’ said Ryan.

  The sandstone edifice of Berner Münster towered over the city, its octagonal bell tower a full hundred metres high. The enormous central entrance arch was flanked by two smaller ones, pleasingly symmetrical, and the whole building was decorated with ornate swirls and crenellations. Inside the central arch, over a hundred tiny stone figures decorated with gilt were frozen in a scene from the Last Judgement.

  ‘Only completed a decade ago,’ said the Doctor. ‘Bit fancy for me.’

  ‘Hello!’ called a uniformed man standing in the doorway of the cathedral. ‘All are welcome; please come in.’

  ‘Police,’ the Doctor noted, strolling over. ‘Why’s there a police officer on the door of a holy place?’

  The man looked surprised. ‘To keep order. With so many people coming …’ He spread his hands. ‘There are ten of us here. Officers have been posted on all the churches in the city. Haven’t you seen the papers?’

  ‘We’ve just arrived,’ said Yaz.

  ‘Come in, come in!’ the officer called to someone over Yaz’s shoulder. A woman holding a baby was crossing the square. She looked up at the sound – and then her gaze jerked higher, and she stopped dead, staring, her mouth opening into a high, terrified scream.

  ‘What’s she seen?’ The Doctor and her friends ran back out into the middle of the square and swung round, looking up.

  ‘I don’t see …’ Graham’s words trailed away.

  Silhouetted against the cold white sky, a huge creature now crouched on the cathedral roof. As they watched, one long brown leg covered in hairs extended itself, followed by another, and another, and the thick brown body rose slightly with the movement. Multiple black eyes shone above pointed mandibles, opening and closing convulsively.

  ‘Not again!’ said Ryan, swallowing.

  ‘Where’d it come from?’ Yaz glanced around nervously.

  ‘Giant spider. Interesting.’ The Doctor aimed the sonic at it and then pursed her lips at the readout. ‘Ooh. That’s interesting too.’ She stepped forward and called up to the giant arachnid. ‘Oi! You and me need to have a little talk.’

  The eight eyes swivelled in her direction.

  ‘I’m the Doctor. And you are?’

  The enormous hairy body hesitated. And then with one swift movement, it gathered its legs and leaped, mandibles open and ready.

  ‘Doctor!’ yelled Yaz.

  The spider fell towards the Doctor – and passed right through her. As it reached the ground, the supposedly solid body splashed silently into smoke, blew up into the air, and drifted away.

  In a matter of seconds, the entire creature had disappeared.

  The Doctor coughed and brushed an imaginary speck off her shoulder. Then she pocketed the sonic. ‘Totally knew that would happen,’ she said to herself. She grinned brightly at the woman on the other side of the square, still frozen in fear. ‘Don’t worry! Just a hallucination from all the stress you’re under!’ She turned to the others and used a pantomime whisper: ‘D’you think she believed me?’

  The woman crossed herself and hurried towards the cathedral, avoiding the Doctor and her companions.

  ‘If we’re doing giant spiders again, I’m going home,’ said Ryan. ‘Once was enough.’

  ‘Wasn’t a spider,’ said the Doctor, shaking her head. ‘Just looked like one. Actually, it was—’

  A high terrified wail came from inside the cathedral, making everyone jump again.

  ‘It’s going to be one of those days, isn’t it?’ Graham said wearily.

  The interior of the cathedral was just as impressive as its exterior. The crisscrossed stone ceiling looked down on a long nave ending in the choir and six stunning stained-glass windows. Stone pillars divided the nave from two side aisles, which opened on to several chapels. The cavernous space was filled with soft noises from the hundreds of people who had sought sanctuary here.

  ‘Oh …’ Yaz said quietly.

  It was hard to register the sheer scale of the view. The pews and chairs were filled, and the mass of humanity spilled out into the aisles, the chapels, the choir. Everywhere Yaz looked, she could see people huddled together, weeping, praying, rocking. And held by the adults, smaller bodies, with closed eyes and pale lips. Lolling heads and limp limbs.

  ‘The children,’ breathed the Doctor beside her. ‘Look at the children.’

  ‘Dear God.’ Graham’s voice was barely a whisper.

  Their faces all had the bluish pallor of Johanna, the girl they had seen in the park. Their chests moved slightly on each inhalation, but there was no other sign of life.

  ‘Why aren’t they in the hospital?’ Ryan said, his voice harsh in the subdued atmosphere.

  ‘Because the doctors have failed us,’ came a bitter reply.

  ‘Friedrich,’ said Yaz, recognising the man from the park. He and his wife Marthe were sitting against a wall, Johanna lain across their laps.

  ‘What do you mean, the doctors have failed you?’ The Doctor crouched down beside them.

  ‘When it started, it was just a few children falling ill,’ Friedrich said. ‘Then it spread and spread. Now every street has a sick child – everyone is terrified. The doctors say they can’t find anything wrong! They are worse than useless. I wouldn’t let a single doctor near my child.’

  The Doctor glanced at her friends. ‘Maybe they don’t know what they’re looking for.’

  Marthe’s eyes narrowed. ‘Who are you?’ she asked suspiciously. ‘You’re not from Bern.’

  ‘No,’ said the Doctor. ‘We only arrived today. Thought we’d drop in on an old friend. That’s Graham, Ryan, and Yaz. And I’m the – er.’ She stopped. ‘I’m Rose.’

  ‘Well, you picked the wrong day to come to Bern, Rose,’ Friedrich told her.

  Johanna whimpered slightly, her eyes flickering under their lids. Marthe clutched her hand. ‘I wish we knew how to help her.’

  ‘It doesn’t affect adults?’ asked Ryan.

  Friedrich shook his head. ‘Only the little ones. The innocents.’ His gaze travelled over to the grand altar at the other end of the nave.

  ‘Of course,’ said the Doctor, understanding. ‘When science fails …’

  ‘Only God can help us,’ Friedrich said.

  The Doctor patted Johanna’s head then got to her feet, hands in her pockets. The others followed her into the shadows.

  ‘This is heartbreaking,’ Graham said quietly.

  Ryan nodded. ‘D’you think it’s got anything to do with the giant spider?’

  ‘Told you, it wasn’t a giant spider,’ the Doctor said. ‘It was made of energy, not mass. That’s why it vanished when it hit the floor. It wasn’t actually solid.’

  ‘Ghost spiders?’ Yaz shuddered. ‘Makes it so much better.’

  ‘Will there be more?’ asked Graham.

  ‘I’ve no idea,’ said the Doctor. ‘But we can’t find out from in here. We need to scope out the area, take some readings. Doctor stuff.’

  ‘Thought your name was Rose,’ Graham said with a small smile.

  ‘Couldn’t call myself “Doctor”, could I? Not after what Friedrich just said. Rose was the first name that popped into my head.’ The Doctor cleared her throat. ‘Graham and Ryan, I need you to stay here and keep an eye on things. Do what you can to help.’

  Ryan nodded. ‘Right.’

  ‘Yaz and I will see what we can find out in the city,’ the Doctor went on. ‘The TARDIS picked up some unusual energy readings, and that ghost spider was a match.’

  ‘Fine time to meet up with your pal Bertie,’ said Graham.

  ‘Isn’t it, though!’ The Doctor grinned. ‘Something science can’t explain? This is right up Albert’s street! Literally, in this case. He lives just round the corner.’

  The late afternoon light was weakening as Yaz followed the Doctor down the near-empty Münstergasse. ‘Keep your eyes and ears open,’ the Doctor instructed. She held out the sonic and swept her arm in a wide circle. ‘There’s a lot of low-level energy noise here; I can’t work out where it’s coming from. It keeps changing, too. Look everywhere, Yaz – up, down, sideways.’

  Yaz felt her senses heightening. Danger could come from any angle; her police training had taught her that, and life with the Doctor had proved it a hundred times over. Her adrenalin spiked as they passed the University Library and a door slammed open. Several men spilled out onto the street, laughing.

  ‘A giant spider, I’m telling you,’ one of them was saying. ‘Crawling up the street. Must have been twenty feet tall.’

  ‘How much beer have you had, Heinz?’ Another man punched him playfully on the shoulder.

  ‘Georg saw it too,’ insisted Heinz. ‘Tell them, Georg.’

  Georg, blond and bespectacled, looked uncomfortable. ‘I don’t know what I saw. But there must be a scientific explanation.’

  ‘Excuse me.’ The Doctor didn’t stand on ceremony. ‘A giant spider, you say?’

  Heinz stared at her. ‘Yes. About half an hour ago. It came up the street here, and then it vanished.’

  The others roared with laughter.

  ‘What happened when it vanished?’ asked the Doctor.

  Heinz shrugged. ‘Don’t know. It turned into a kind of smoke. Then it just blew away.’

  ‘Exactly what happened to us!’ the Doctor exclaimed to Yaz. ‘The same thing in two different places, and at around the same time it sounds like. Curiouser and curiouser, as I once said to my old pal Charlie Dodgson. Which way did the smoke go, Heinz?’

  Heinz pointed and, with a hurried thanks, the Doctor and Yaz set off again.

  ‘Even energy has to go somewhere,’ the Doctor said to Yaz. ‘If we can find the source …’

  They reached the end of the street, the Doctor scanning as they went, and turned into Kramgasse, stepping over the tram lines that ran down the centre. Solid stone walls rose up impressively either side of the road. On the ground floor were arcades fronting shop windows. Above were the tall rectangular windows of apartments, rising to three storeys. This was clearly a busy shopping and trading area on a normal day, but today only a handful of people were around, talking soberly in small groups, or glancing fearfully from side to side as they went. There were no children in sight. One woman was being comforted by a friend, her tear-streaked face telling its own story.

  ‘Things are really bad,’ Yaz said.

  The Doctor nodded grimly. ‘It’ll be good to get Albert’s take on this. He always sees things differently. Nearly there now – number 49.’

  Yaz followed the Doctor under an arch and up a very narrow spiral staircase to the second floor. Here there was a simple door with a knocker and the handwritten label ‘Einstein’ at head height.

  The Doctor reached for the knocker and then paused. Voices could be heard from inside – loud, angry voices.

  ‘It was just a spider!’ a woman was shouting. ‘You’re being ridiculous!’

  ‘It was deadly!’ a man cried back. ‘I’ve read about them. They can kill within seconds!’

  ‘It’s a house spider, Albert, we get them all the time. I am not contacting the police to tell them you’ve imagined up a poisonous spider.’

  ‘Show them the body!’ Albert screamed. ‘Then they’ll see!’

  The Doctor and Yaz glanced at each other with raised eyebrows. ‘A spider?’ murmured the Doctor. Then she knocked loudly.

  The voices inside stopped abruptly. Footsteps came, and the door opened into a small hallway. A woman stood there, flustered and self-conscious. She had a soft round face and dark hair swept back from her forehead into a loose bun. ‘Yes?’

  ‘Mileva, good to see you again!’ The Doctor stepped forward to embrace her.

  The woman jerked back. ‘Who are you?’

  The Doctor laughed apologetically. ‘Of course, you haven’t met this face before. Sorry. I was at your wedding.’

  ‘What?’ Mileva glanced uneasily down the hallway. ‘I’m not married. Yet.’

  ‘You’re not? Ah!’ The Doctor turned to Yaz. ‘This is just before the wedding I told you about. We’re cutting it a bit fine, I must say.’ She beamed at Mileva. ‘We’re, uh, friends – well, at this point, colleagues – of your fiancé. I’m the Doctor and this is Yaz.’

  ‘This is not a good time.’

  ‘No, but it’s the right time.’ The Doctor smiled hopefully. ‘Whatever’s going on, I’m pretty sure we can help.’

  Mileva gave an exasperated shrug. ‘You’d better come in. I would say excuse the mess, but it’s always like this.’

  Indeed, the small sitting room they were ushered into was covered in piles of paper with handwritten notes, textbooks, bits of scientific apparatus, and pots of ink.

  Twitching in a corner, looking at the same time aggressive and terrified, was a short man with slicked-back hair. His moustache looked somewhat hopeful rather than impressive.

  Yaz’s jaw dropped. ‘Is that him? He doesn’t look anything like his picture!’

  ‘Who are you? What’s going on?’ The man had a round face like the woman, though his eyes were fiercer. ‘Are you from the police? I need to report a dangerous animal.’

  ‘The Doctor and Yaz,’ said Mileva patiently. ‘They are colleagues of yours, from England, I think?’

  ‘Near enough,’ said the Doctor.

  Albert’s eyes narrowed. ‘I don’t recognise them.’

  ‘Are you working on one of your Theories?’ Yaz reached out to a pile of papers.

  ‘Don’t touch that!’ Albert snapped out. ‘I was working, until I was attacked by a deadly arachnid.’

  ‘What happened to it?’ asked the Doctor.

  ‘I can show you!’ Albert said triumphantly. ‘It happened not half an hour ago. I kept its body – look!’ He held out a glass jar, lid tightly closed. Inside was the curled over body of a large but common house spider. ‘I killed it!’ Albert announced. ‘You can see the venom dripping from its fangs, ready to inject into me!’

  The Doctor and Yaz peered at the body. There were no fangs, no venom. The Doctor flicked a glance at Yaz. ‘Gosh,’ she said. ‘You had a lucky escape there, Mr Einstein. Looks like an Arachne fatalis mendax to me. We’ll take this back to the lab and run some tests on it.’ She pocketed the jar.

  Albert seemed to relax. ‘Good, good,’ he said, nodding. ‘Excellent. Need to find out if there are any more of these around. There could be an infestation. And that reminds me.’ He stiffened as he looked back to Mileva. ‘I heard a rat.’

  ‘We’ve been over this, sweetheart,’ Mileva said gently.

  ‘I did!’ Albert ran his hand through his hair so that it stuck up in tufts. A feverish light appeared in his eyes. ‘I heard it in the walls.’ As Mileva reached out to pat Albert on the arm, he recoiled. ‘Your wrist! What is that on your skin?’

  Puzzled, Mileva held up her hand. ‘Nothing. A small burn from the iron yesterday.’

  ‘Blisters,’ Albert insisted. ‘Red, weeping – you should see a doctor. You!’ He swung round to his visitors. ‘One of you is a doctor! Look at her – can’t you see the disease eating through the skin?’

  Mileva’s lip trembled. ‘Albert – darling …’

  ‘Why don’t you come into the kitchen and show me?’ suggested the Doctor. ‘Then I can clean it if I need to.’

  Albert nodded. ‘Yes. It looks contagious.’

  The Doctor ushered Mileva out of the room and Yaz followed. Tears were flowing down Mileva’s face. In the tiny kitchen, she held up her wrist. ‘See, just a small red mark! He is imagining it all!’

  The Doctor nodded. ‘Something’s badly wrong with him.’ She pulled the jar out of her pocket. ‘Bit of a coincidence that Albert was hallucinating about a deadly spider around the time we saw one outside the cathedral.’

  A door slammed. Mileva whipped round. ‘Albert!’ They heard footsteps going down the stairs outside.

  ‘Best to let him go for now,’ said the Doctor. ‘I could do with taking some readings.’ She went back through to the sitting room and started scanning with the sonic. ‘Hmm. Hardly anything here now …’

  Yaz helped a sobbing Mileva to a chair. ‘We’ve come through so much already,’ said Mileva, a handkerchief clutched to her face. ‘How can we marry if he’s not in his right mind? He’ll have to go home. His mother at least will be pleased,’ she added bitterly.

  ‘His mother?’ Yaz moved some books off a nearby chair and sat down next to her.

  Mileva sniffed. ‘She’s always hated me. She wants Albert to marry a nice German girl, and I’m Serbian. But love is what it is, no? You cannot choose where your heart finds its home. And I have loved him since we met. Since we took the same Physics class at the Polytechnic.’ She looked up at a photograph on the wall that showed the two of them together. ‘Six years ago. Six long years, and so often apart. When we were together, we were like molecules bonding. When apart, we shared our minds in letters. We even had pet names for each other.’ She looked down at her hands. ‘He is my soulmate.’

  ‘I’m sure he’ll come round,’ Yaz said softly. ‘And I know you’ll be married. Right, Doctor?’

  But the Doctor was pulling a face. ‘Only if things work out as they should here,’ she said. ‘The future could change. It’s all relative, space and time.’ She looked sharply at Mileva. ‘Forget you heard that.’

  But Mileva was distracted by a sound from outside. ‘What’s that?’ She went to the window and pulled it open. The three of them leaned out over the ledge to look down into the street, where a dark cloud was growing. A skittering sound could be heard.

  The Doctor pulled out the sonic which buzzed. ‘It’s the same energy that made the spider! Only, it’s much stronger …’