The Door That Led to Where by Sally Gardner

slept in so long and the atmosphere in the room wasn’t exactly conducive to being alert. He must have nodded off, but he woke with a start as soon as he heard his name. The mask that had been on Mr Baldwin’s face had been taken off.
    â€˜You have five minutes and no longer, Mr Baldwin,’ said the nurse, looking anxiously at her patient.
    Mr Baldwin waved her away.
    â€˜Listen to me and listen carefully,’ he said to AJ, his tight words held together by a lack of emotion. ‘This is important. The documentation that authenticates the snuffboxes in the Purcell case is at Samuel Dalton’s house in Clerkenwell. Do you know where that is?’
    Lying seemed pointless. AJ nodded.
    â€˜I take it Ingleby found you?’
    AJ nodded again.
    Baldwin’s tongue flicked in and out of his mouth.
    â€˜It is imperative that you find the papers and give them to Ms Finch. They are vital to the defence of our client. Do you understand?’
    â€˜Yes, sir,’ said AJ.
    â€˜Good. I am fighting this sickness and I will win. I am not going to die, Aiden – neither am I going to lose the case or my reputation.’ A hand with a drip attached to it grabbed hold of AJ’s arm with unexpected strength. ‘Have you locked the door?’
    â€˜No, sir.’
    â€˜So you have the key, then. Whatever you do, do not lock the door. When you’ve found the papers you will return the key to me. And you will mention it to no one, no one. It will be our secret and I will take the matter of your stealing it no further. Your job – your future – will be secure. Do I make myself clear?’
    AJ nodded.
    Baldwin closed his eyes.
    The nurse came back and fitted the mask over the lawyer’s mouth. The visit was over.
    Outside, the toxic fumes of Marylebone Road smelled good and AJ took deep gulps. Everything had gone tits up. Perhaps the professor would be able to put him straight about a few things. He should be at the café at Rosebery Avenue by now.
    AJ fell asleep on the bus. His phone woke him up and he was relieved to see Slim’s familiar number. The sky exploded with rockets trailing stars of light. AJ had forgotten it was Guy Fawkes’ Night.
    â€˜Where are you?’ Slim said.
    â€˜On my way back from work. What’s up? Is everything all right?’
    There was silence at the other end. Another firework roared into the sky.
    â€˜Slim,’ said AJ. ‘Is it Moses?’
    â€˜No, nothing like that. Look my phone is about to crash. I’ve something to  … ’
    Slim’s phone died. AJ tried to call him back but couldn’t get through. By the time he had arrived at Mount Pleasant he had put Slim’s call out of his mind.
    AJ found the café the professor had taken him to. He had the change from the taxi fare and he went in, sat down at a table by the window, and used it to fund a feast.
    â€˜May I join you?’
    â€˜Bloody hell! Where did you spring from?’ said AJ.
    â€˜A nice waistcoat and a shirt of the finest cambric,’ said the professor, sitting down. ‘Have your wages gone up, AJ?’
    â€˜No.’
    â€˜Then you now know the answer to the riddle of my pocket watch.’
    AJ drank his tea.
    â€˜I now have several riddles, all of which have one thing in common: a key. It seems that I have the only key to a door, and I am the only person who can lock it but at this moment it’s open to anyone who knows about it. Mr Baldwin said that unless I return the key to him he is going to bust me, and Mr Stone with four eyes said I must lock the door and post the key back.’
    The professor interrupted him.
    â€˜But you haven’t, have you, AJ?’
    â€˜Haven’t what?’
    â€˜Haven’t locked the door and posted the key through the letterbox?’
    The professor’s eyes never left AJ’s.
    â€˜No. I still have it on me.’
    The professor sighed.
    â€˜I am glad to hear