‘Mickey, mate, do us a favour?’ said Skins as Mickey rose to leave. ‘Can you nip down the chapel and pack up my drum set? You know where everything goes.’

  ‘What did your last servant die of?’ said Mickey.

  ‘I drugged him and threw him in the Thames for his insolence. Look, we’ve got one or two things to do . . . You know . . . about the you-know-what. Just pack up for me – I might not have time.’

  Mickey nodded sagely. ‘Say no more, mate. Consider it done.’

  ‘Thanks. If anyone asks, you’ve not seen us.’

  ‘Mum’s the word.’

  Mickey left the three friends and their lookout to wait for their chance to go exploring.

  They sent Veronica on a scouting mission and she came back to report that most of the family seemed to have returned to their rooms, while Peter and Elizabeth were bickering in the drawing room.

  ‘Oh dear,’ said Ellie. ‘What about?’

  ‘Oh, the usual. She was berating him for not being ambitious enough, and for letting Father push him around. There was the usual thing about Papa thinking Peter was a gold-digger. He pointed out that her father wouldn’t be able to do that now he was dead, and that he was about to start working with her brother as the company’s lawyer. He didn’t add, “So yah-boo to you,” but it was implied.’

  ‘It’s all working out for Pete, then,’ said Skins. ‘Is he the sort who could kill? Even if it was just to get his fiancée off his back?’

  ‘To be honest I’ve always assumed he likes the nagging. I can barely put up with her myself, but I don’t have so much of a choice – one is rather lumbered with family, like it or not. But he could walk away at any time, so I thought he must enjoy it.’

  Skins laughed. ‘Probably not the murdering type, then. But other than those two, the coast’s clear?’

  ‘There’s no one else about.’

  ‘Let’s do it, then,’ said Ellie. ‘I’m dying to see what’s down there.’

  Skins showed them how the latch worked and pushed the bookcase inwards.

  ‘After you, then, Ells-Bells,’ he said. ‘Light switch is next to you, there.’

  Ellie turned on the light and trod carefully down the stone stairs with Skins close behind. Once he’d made his own way inside, Dunn turned round and, with a wink, started to push the bookcase back into place.

  ‘We’ll knock like this’ – he tapped ‘Shave and a Haircut’ on the wood – ‘when we’re ready to come out. If it’s all clear, tap the same rhythm back – not the two knocks anyone else would do. That way we’ll know it’s you and that it’s all right to come out. We can open the door from in here.’

  ‘Got it. Good luck. Bring me back a present.’

  Dunn laughed and clicked the bookcase closed.

  At the bottom of the steps was a room that seemed identical to the one beneath the study. This one, though, was free of furniture and postcards. The other glaring difference was an iron-bound oak door on the outside wall.

  ‘That’s old,’ said Ellie. ‘Much older than the house.’

  ‘Elizabethan?’ asked Skins.

  ‘Could be,’ she said. ‘Could be.’

  ‘Ah, I get it,’ said Dunn. ‘So this could be left over from the original house. Which might mean it leads to—’

  ‘The chapel,’ said Skins and Ellie together.

  ‘Well, don’t just stand there, you idiots. Open it.’

  Ellie grasped the ring handle and turned it to lift the latch. The door swung towards them on oiled hinges to reveal an arched, brick-lined tunnel.

  To their surprise, the tunnel was lit.

  ‘Those bulbs aren’t an original feature,’ said Dunn.

  Skins pointed to the cables that ran from a hole in the wall above their heads to the right, went through a hole drilled in the old doorframe and then off down the tunnel. ‘They’ve got all the modern amenities here, mate. Someone’s wired it all up.’

  Ellie led them off down the tunnel. It was tall enough for her to stand upright and she progressed quickly. Skins was fine as long as he remembered to duck for the lightbulbs hung at intervals from the roof. Dunn, though, was forced to crouch uncomfortably.

  ‘People were a lot shorter in the olden days,’ he said as he banged his head on the brick roof for the umpteenth time.

  ‘Maybe it’s just Catholic priests who were short,’ said Skins.

  ‘Or maybe Barty’s freakishly tall,’ suggested Ellie. ‘We’re having no trouble at all.’

  ‘Or maybe he’s normal, and I’m descended from a long line of priests.’

  ‘Pause a while and see if you can work out why that’s impossible,’ said Dunn. ‘You idiot.’

  Skins chuckled. ‘You make a good point, Barty boy. Now all we need to do is work out why this tunnel is so twisty-turny. You’d think it would be easier just to cut it in a straight line from the chapel to the house.’

  Dunn thought for a moment. ‘How about this? Suppose you were a priest. Suppose you were saying mass in the chapel and the queen’s agents burst in. You manage to leg it down the escape tunnel, but they follow you. If the tunnel is straight, they can see you, no matter how far you’ve run. One of them has a crossbow. Or a gun. Did they have guns? Anyway, if the tunnel’s straight they’ve got a clear shot and you’re a dead priest with no one to give you the last rites. But if it’s a little bit twisty like this one, you don’t have to be far ahead for them not to be able to even see you, let alone take pot shots at you.’

  ‘You’re much cleverer than you look, Barty Dunn,’ said Ellie.

  ‘He’d have to be,’ said Skins, ducking the slap aimed at the back of his head. ‘How far do you reckon we’ve come?’

  ‘I’ve no idea any more,’ said Ellie. ‘I started counting steps but then you started wittering on about short priests and crossbows and I lost count.’

  ‘However far it is,’ said Dunn, ‘we’re there. Look.’

  A short way ahead of them was another oaken door. Ellie approached and confidently turned the ring handle. The door was locked.

  ‘Oh,’ said Dunn. ‘That’s disappointing.’

  ‘Not wholly unexpected, though,’ said Ellie. ‘To be honest I was surprised the first one opened.’

  ‘What do you reckon, then? Back to the library for a rethink?’

  Skins nodded. ‘Lead the way, Lofty. And mind your head.’

  Back in the library, Veronica poured them all a cup of tea while they told her what they’d found.

  ‘How very thrilling,’ she said. ‘Do you think you got as far as the chapel?’

  ‘I tried counting my steps on the way there and the way back,’ said Ellie, ‘but these two idiots kept joking about and I lost count both times. We must have been most of the way there, though.’

  ‘It might come up outside,’ said Dunn. ‘A lot of those secret tunnels do.’

  ‘How do you know?’ asked Skins.

  ‘I live alone. I read.’

  ‘How do they emerge, though?’ said Veronica. ‘Trapdoors?’

  ‘Some have trapdoors,’ said Dunn. ‘Some are hidden in follies or grottoes. I read of one that came out at the back of a natural cave.’

  ‘We’ve nothing like that in the grounds. We might have missed the secret doors, but we’d know all about follies, grottoes and caves.’

  ‘Oh. Well in that case, if it opens anywhere at all it’s probably in the chapel itself. Can you think of a likely spot?’

  ‘There’s a cupboard just inside the main door.’

  ‘Gordon could easily have slipped into a cupboard while no one was looking,’ said Skins.

  Dunn was less convinced. ‘Is it big, this cupboard? Big enough for someone to get in, close the door, then open a secret trapdoor?’

  ‘Probably not,’ said Veronica.

  ‘You’d not want a tunnel entrance right by the main door,’ said Skins. ‘That’s where the bad guys would be. “Excuse me, would you mind awfully stepping aside, only you’re blocking my secret escape route.” You’d want it in the body of the chapel somewhere.’

  ‘Not the body,’ said Ellie. ‘In one of the side rooms. You’d need to be able to run, hide, lock yourself in and then disappear. If it comes out anywhere it’ll be in the bathroom or the control room.’

  ‘It’ll be the bathroom, then,’ said Skins. ‘You said before that everyone was back and forth to the loo. Gordon could have snuck off to powder his nose any time after John left. Who would have noticed how long it took him to get back?’

  ‘We need to find the key,’ said Dunn.

  ‘Well, quite,’ said Veronica. ‘But that’s easier said than done, wouldn’t you say? I mean, I’ve lived here since I was two and I’ve only just learned that there are two secret rooms and a tunnel in the house. And think how big a secret room is compared with a key.’

  ‘It’s got to be easy to get hold of,’ said Dunn. ‘If you were planning to make use of the tunnel, you’d not want to be ferreting about for the key. You’d want it close at hand.’

  ‘Or in your pocket,’ said Skins. ‘We might never find it if the killer has it.’

  ‘I wouldn’t keep it with me,’ said Ellie. ‘It’s incriminating evidence, for one thing – I wouldn’t want to be caught with the key that might help to prove I murdered John Bilverton.’

  ‘Good point,’ said Dunn. ‘And if more than one person knows about the tunnel, it’s a bit of a giveaway if the key goes missing.’

  ‘All right, then,’ said Skins. ‘But where would you keep it? If you keep it in the house, you can’t get out of the chapel. If you keep it in the chapel you can’t get through the tunnel from here.’

  ‘Two keys?’ suggested Ellie. ‘One at either end?’

  ‘I suppose that would do it. But it’s a big old house and a big old chapel. Where do we start? The study? Or the butler’s pantry? There were dozens of keys on that board in there.’

  ‘It’s hardly a secret tunnel if the butler has a key,’ said Dunn. ‘But it would be near the secret door itself. That’s obvious, isn’t it? If it exists at all, it’s got to be in here.’

  Skins swept his arm around the room. ‘Somewhere in here, then. Among these hundreds of books—’

  ‘Thousands,’ interrupted Veronica.

  ‘Among these thousands of books and dozens of knick-knacks. Where do we even start?’

  ‘We think like a sneaky person,’ said Ellie. ‘If you were trying to keep the key available, it would be near the secret door, just as Barty says. But you wouldn’t want it too close. If someone stumbles upon how to open the door, like we did—’

  ‘I didn’t stumble,’ said Skins. ‘I reasoned it out with the power of my towering intellect.’

  ‘If someone figures out there’s a secret door here by the sheer, breathtaking brilliance of their mighty brain—’

  ‘That’s more like it.’

  ‘—then you wouldn’t want them just to stumble on the key as well, no matter how powerful their brain might be. So I suggest we can rule out the whole of this side of the bookcase.’ She indicated the section to the right of the fireplace. ‘But you’d still want it to be handy, so I think we can rule out the other end of the room down towards the salon door as well.’ She moved over to the left of the fireplace and pointed to the bookcase there. ‘Which leaves this side.’ She turned to her left. ‘These shelves as far as the window.’ She turned right round. ‘And that section over there as far as the door. Barty? You and Ivor take those, Veronica can search up to the window and I’ll take these shelves by the fireplace.’

  ‘What are we looking for?’ asked Veronica. ‘What was the lock like? Big? Little?’

  ‘It was a big, old-fashioned lock,’ said Dunn. ‘So the key is going to be chunky. Probably ornate, too – they went in for fancy keys in the olden days.’ He held up his hands to indicate a key about four inches long. ‘Something like that.’

  ‘Right you are,’ she said. ‘Are we considering hollowed-out books?’

  ‘I’ve always wanted to find something in a hollowed-out book,’ said Skins.

  ‘I guess we’ll have to consider them in the end,’ said Ellie, ‘but I’d start with looking in trinkets first. Anything that might open, even if it’s not an actual box. Then we can look behind the books. And then, Ivor my darling, we can start opening them up and seeing if someone has cut a compartment in the pages to conceal a key.’

  ‘That’s all I ask,’ he said.

  They began their search.

  Veronica took down a porcelain figurine of a geisha wearing a blue kimono, and shook it. It belatedly occurred to her that if there were a heavy iron key inside it might smash the delicate china, but it appeared to be empty anyway. She peered into the hole in the base in case the key might be wrapped in something to prevent it rattling, but there was definitely nothing there.

  She moved on to a Japanese puzzle box. She’d played with it as a girl and had long since worked out the secret of opening it. Inside, exactly as she remembered, were three coins and a jade bracelet. But no key. She closed the box and put it back on the shelf.

  Skins and Dunn were also examining figurines with a similar lack of success, though theirs were European in origin.

  Skins held up a figure of a woman in a floral dress wearing a long green jacket. She was sitting on a chair and holding a book while she stared into the middle distance with a vacant look on her face. ‘No offence, Veronica, but this is hideous.’

  ‘None taken,’ she said. ‘There are some absolutely ghastly things in this house. I used to long to break some of them – that one in particular.’

  ‘You must come and visit us in London,’ said Ellie. ‘We have a porcelain ballerina that’s badly in need of smashing, but the children never seem to manage it.’

  ‘I should love to visit, porcelain ballerina or not. And when I do, just point it out to me and I’ll do my best to bump into it for you.’

  ‘Come for dinner when all this is over.’

  Dunn held up a dark blue Fabergé-style egg. ‘Does this open? Or will I break it if I try?’

  ‘Twist the crown thing on the top and it’ll pop open.’

  The egg did, indeed, pop open to reveal a posy of enamelled violets. But no key.

  The trinkets on Ellie’s section of bookcase were all too small to hold the sort of key they thought they were looking for, so she had started removing the books one by one to see what was behind them.

  The top shelf had yielded nothing, as had the second. She was working her way along the third when a title caught her eye.

  ‘Would you guys hide the key to a priest’s secret escape tunnel in a book called The Mysteries of the Elizabethan House?’

  Skins stopped what he was doing at once and excitedly crossed the room. ‘Open it and find out.’

  Ellie pulled the book from the shelf. It was bound in dark red leather with the title debossed and picked out in gold leaf. It was hefty and, to their shared joy, made a clonking sound when she shook it. She lifted the cover, expecting to be able to leaf through the book, but almost all the pages had been glued together. Just two remained unglued so that the cover and the first few pages formed the lid of a heavy paper box, inside which was a chunky iron key.

  ‘Well, that’s not disappointing at all,’ said Dunn. ‘Shall we see if it works?’

  Chapter Fifteen

  With Veronica on watch in the library, Ellie led the way along the tunnel, muttering under her breath.

  ‘You counting, Ells-Bells?’ said Skins.

  ‘She might be,’ said Dunn. ‘Although I can think of twenty-six, maybe thirty-five reasons why she might not.’

  ‘Oh, I’d have put it lower than that. I can only think of six or seven. Twelve at the most.’

  ‘You’re a couple of stinkers, you know that,’ said Ellie. ‘I’ve a good mind to take us back to the entrance and start again.’

  ‘It doesn’t matter now,’ said Dunn. ‘If the key opens the door, we’ll find out where it goes without having to count anything.’

  ‘You’re still a stinker. And you’re a double stinker, Ivor Maloney.’

  ‘What have I done? He started it.’

  ‘You joined in. You should defend me.’

  ‘You’re big and scary enough to defend yourself, my angel. We’re here now, anyway.’

  Ellie fitted the key into the lock and turned it. With a well-oiled clonk, the bolt withdrew. She turned the ring handle. The latch lifted, and the door swung open.

  Ahead was another stretch of tunnel, exactly like the section they had already come through.

  ‘See, now, if you stinkers had let me count, we’d have known we were only part way there.’

  ‘There can’t be much further to go,’ said Dunn. ‘Just round this next bend, I reckon.’

  Skins shook his head. ‘I say two more bends.’

  ‘Half a crown?’

  ‘You’re on.’

  Two more bends later they reached a third oak door and Dunn fished in his pocket for two shillings and sixpence to settle the bet.

  Ellie tried the door and was relieved to find it unlocked. It opened into a small empty room, lit with an electric lightbulb hung from the same cables that ran the length of the tunnel. There was a flight of stone stairs in the corner of the room, disappearing up into the ceiling.

  ‘You guys want to place a bet on where that leads?’ she asked.

  ‘Bathroom,’ they said together.

  She laughed. ‘I agree, actually. Come on, let’s find out.’

  She led the way up the steps and found herself in front of a blank wall. It was darker at the top of the stairs, but it was obviously a dead end.

  She started running her hands over the smooth plaster. ‘We’d all have lost our money – it doesn’t go anywhere.’

  ‘It must do,’ said Skins. ‘Is it another trick door like at the other end?’

  ‘Already looking, honey. Give me a second.’

  Her fingertips brushed over a crack in the plaster. She traced it upwards. The crack was straight and vertical.

  ‘Feels like there’s a door here,’ she said. ‘I’m looking for the latch.’

  With a click, the crack widened and a section of the wall moved slightly away.

  ‘Found it.’