The scene out on the streets was every bit as bad as inside the hospital. Faces of the Shroud were bulging out all around them, trapping their victims with their psychic probes. People stared in horror at them, tears streaming down their faces.

‘This is terrible!’ cried Clara, standing in the back of the ambulance and clinging on to the seats. ‘We have to help them.’

‘We will,’ the Doctor assured her. ‘We can’t deal with each face individually – for every one we get rid of, dozens more would sprout up. I have to get to the source and stop it from there.’

‘Like turning off a faucet?’ said Mae.

‘Exactly,’ beamed the Doctor. ‘A freaky face-filled faucet!’

‘I don’t get it,’ said Mae. ‘I’ve seen faces in things ever since I was little. There was one on the pattern of my wallpaper when I was a kid, and another made of mildew on the bathroom ceiling of my dorm room at college. It always came back, no matter how many times I washed it away. None of my roommates ever seemed to notice it, though. Or attempted to clean it up, for that matter.’

‘Some people are more susceptible to psychic influences,’ explained the Doctor. He spun the steering wheel to avoid an elderly woman kneeling in the road, deep in conversation with the head of a young boy peeking out from behind a mailbox. ‘You see a face hidden in a seemingly random design or an arrangement of objects, and other people don’t. It just means you’re a more powerful receiver than they are.’

‘So I’ve been surrounded by aliens all my life?’

The Doctor nodded. ‘You’d be surprised how often that happens.’

‘But why?’ asked Clara. ‘If the Shroud have been here for so long, why wait until now to reveal themselves?’

‘I don’t know,’ admitted the Doctor, ‘but I’m going to find out.’ Suddenly, he hit the brakes.

‘What’s wrong?’ asked Clara.

‘I almost missed it,’ said the Doctor, swinging the ambulance around.

‘Missed what?’

‘That old lady wasn’t crying.’

The Doctor pulled up across the street from the woman, and jumped out of the ambulance. ‘Hello!’ he called, striding over. ‘I’m the Doctor. What seems to be the trouble?’

The woman looked up, concern etched across her features. ‘This is Sammy,’ she said, indicating the young boy hiding in the bushes. ‘He lives in my building, two floors above me. I came out to mail a letter and found him here.’

‘Hello, Sammy,’ said the Doctor. ‘Weird day, huh?’

The young boy didn’t reply.

‘Lots of funny faces poking out from the walls and stuff,’ continued the Doctor. ‘Did you see any of those?’

Sammy nodded. ‘My mom did.’

‘Where’s your mom now?’ asked the Doctor.

‘In our apartment,’ Sammy replied. ‘Talking to my dad.’

‘Then why are you out here? Don’t you want to talk to your dad, too?’

‘My dad’s in Heaven. My mom is crying.’

‘Ah, I see.’

The elderly woman smiled. ‘I asked Sammy if he’d like to come and wait in my apartment until his mom feels better,’ she said. ‘I thought we could eat cookies and watch cartoons on television together. I’ve just baked a fresh batch of raisin bran.’

‘Now, that sounds like a good idea,’ said the Doctor. ‘I can’t think of anything better to prescribe on a day like this than a good dose of Loony Tunes and raisin bran cookies – and I’m a doctor. What do you say, Sammy?’

The young boy shook his head. ‘My mom says I’m not allowed to talk to people I don’t know.’

‘She sounds very wise,’ said the Doctor, ‘but I think she wouldn’t mind on this occasion. And you do live in the same building as …’ he turned to the woman.

‘Edith,’ she said. ‘Edith Thomas.’

The Doctor shook her hand. ‘Delighted to meet you, Edith Thomas,’ he said. ‘Have you seen Edith before today, Sammy?’

The boy nodded. ‘I see her when I’m on my way to get the school bus.’

‘And what does Edith do when she sees you on your way to school?’

‘She smiles at me.’

The Doctor leaned in and whispered. ‘Then I think she might be quite friendly. And,’ he paused to sniff at the woman, ‘from the smell of her, those cookies are going to be great! Now, how about if you go with Edith back to her apartment and watch some cartoons? Then I’ll find a way to cheer your mom up, and you can go back upstairs.’

Sammy eyed the Doctor cautiously. ‘You can help my mom feel better?’

‘I’m the Doctor. I make everyone feel better.’

‘OK …’ said the boy, accepting Edith’s hand. The Doctor watched as she led him inside the apartment building, then returned to the ambulance.

They drove in silence for a few blocks. Mae stared out of the window, running her fingers over the bandage covering her wound. ‘I wasn’t after her money,’ she said eventually. ‘What my grandma said about me earlier. It wasn’t true.’

‘That face wasn’t your grandma,’ said the Doctor. ‘It was just using your memories of her to upset you.’

Mae felt her eyes begin to grow wet again. ‘Well, it worked.’

‘Don’t let it,’ said the Doctor. ‘That’s what the Shroud wants. To feed on your sorrow.’

‘It feeds on grief?’ said Mae, looking bewildered.

‘As far as I can tell,’ said the Doctor. ‘And it’s ravenously hungry.’

‘Is that why we all saw someone different on the TARDIS door?’ asked Clara.

‘It was reaching out to all three of us,’ said the Doctor. ‘Trying to decide which of us was easiest to manipulate. Which of us would provide it with the tastiest meal.’

Clara looked shocked. ‘But messing with your memories like that. It’s …’

‘It’s horrible,’ finished the Doctor, ‘and incredibly difficult. It means the Shroud are powerful. Powerful enough to twist your memories of a loved one, like it did with Mae. It uses guilt to add to the sense of loss you already feel.’

He turned a corner and hit the brakes again. There was a police car blocking the road.

‘Sorry,’ said Mae, ‘I forgot. We can’t go through Dealey Plaza, the police still have it sealed off after yesterday.’

Suddenly, the Doctor slapped his palm to his forehead. ‘Why didn’t I think of it sooner?’ he cried. ‘Yesterday! The assassination of President Kennedy! The entire country is in mourning. That’s what the Shroud have been waiting for.’

‘Why?’ asked Clara. ‘What does that have to do with all this?’

‘Everything,’ replied the Doctor. ‘The faces have been around for years, hanging about, looking all freaky. But they were waiting for something. Something that would give them enough energy to make that final push through from the wormhole.’

‘A national tragedy,’ said Mae.

‘A global tragedy,’ said the Doctor. ‘The entire world grieving. It’s like we’ve laid on a giant banquet for the Shroud.’

‘That’s why I know the name of the hospital!’ exclaimed Clara. ‘We learned all about it at school. Parkland Memorial was where they took the President’s body for his autopsy. No wonder everyone looked so down when we first arrived.’

‘And Mae’s office has been covering the story,’ said the Doctor. ‘What were you doing just before you first saw the face of your grandmother?’

‘Looking through some photographs of the shooting,’ said Mae. ‘They were horrible.’

‘And they upset you?’

‘Of course!’

‘That’s why your office and the hospital were affected first,’ said the Doctor, reversing the ambulance back up the street. ‘The places where emotion is strongest will be the weakest points for the Shroud to break through.’

‘But it’s spreading fast,’ said Clara, ‘and, like you said, it’s a global tragedy. That means …’

‘The same thing is going to happen all over the world,’ said the Doctor. ‘We have to get to Mae’s office now. If we can’t stop this, then no one will ever smile again.’

‘It was right there,’ said Mae, pointing to the coffee stain at the edge of her desk. ‘I saw it!’

The Doctor buzzed the sonic screwdriver over the collection of brown rings and marks, then checked the results. ‘Well, there’s nothing there now,’ he said. ‘Nothing but bad coffee and old varnish.’ He turned to Clara. ‘How about you?’ he asked. ‘Any sign of your uncle?’