mind, like balls on a roulette wheel, waiting to see where they’d land. Knightley knew from experience not to disturb his son during this process. Instead he watched with a mixture of awe and the faintest hint of professional jealousy.
‘Be so kind as to repeat the sequence again,’ said Darkus with his eyes still closed.
Knightley read the code the way a bingo caller announces the lucky numbers. ‘Fifty-three, sixty-four, chance … a relay … thirteen-thirty-nine.’
Darkus remained silent, examining the vortex of possibilities in his head. Then he began to speak quietly: ‘Once you stop trying to make sense of it, and just listen to the sounds themselves, a familiar pattern presents itself.’
Knightley raised his eyebrows. ‘It does?’ he said, surprised.
‘Yes,’ answered his son. ‘Underwood has a speech impediment that appears to have garbled what would otherwise be a perfectly comprehensible message – either spoken deliberately, or by accident, before he lost consciouness.’
‘You mean like a slip-up of the mind. A “brain fart” I believe it’s known as,’ Knightley speculated, before censuring himself: ‘Sorry, do proceed. How did you arrive at this deduction?’
‘Simple,’ said Darkus. ‘Why else would Underwood give us the location of a safe deposit box in Central London?’
‘A safe deposit box? How could you possibly know that?’
‘It’s not “chance, a relay”. It’s “Chancery Lane”. The Chancery Lane Safe Deposit Company is the oldest andmost trusted in London. The address is fifty-three to sixty-four Chancery Lane. Therefore we can assume that the number of the safe deposit box is identified by the remaining digits in the sequence: one-three-three-nine.’
‘Outstanding,’ said Knightley, shaking his head in admiration. ‘You’ve still got it, Doc.’ He guided his son towards their trusty, souped-up London black cab that was parked in the shadows.
‘But you’re still not getting it, Dad.’ Darkus resisted his father’s guidance. ‘Consider this solution a farewell gift.’
‘A farewell? From what?’
‘From the business. I’m not coming back to work, Dad. I’ve got GCSEs next year. And a lot of catching up to do … in all kinds of ways.’
‘I’m afraid it’s my turn to be rational. Tilly’s told me about you and Alexis, and her slightly … left-of-centre ideas.’
Darkus waited to see where this was going.
‘I know this is about Wilbur,’ said his father gently. ‘I know how much it hurt you, but I never could have predicted that outcome –’
‘I don’t want to talk about that right now.’
‘I loved that mutt as much as you did.’
‘Did you?’ Darkus challenged him, feeling his chest tighten with emotion.
‘I never wanted this line of work for you, Doc. But we both have to accept that detective work’s in your blood. There’s no escaping it.’
Darkus took a deep breath, then answered, ‘Congratulations on apprehending Underwood. I’m certain you’ll crack the Combination soon enough. Goodnight, Dad.’
Darkus started walking away, feeling a childish sense of victory, tempered with an unsettling, nauseous feeling in his stomach.
‘The Combination is a revolving door, you know that,’ his father implored. ‘One leader falls, another takes their place. Until we get them all in one place, crack the mechanism and take it apart, they’ll always be out there. They’ll never stop …’
‘I hope you and Tilly find what you’re looking for,’ Darkus responded, before turning away.
Knightley’s arms dropped to his sides and he stood on the pavement, hopeless, as his son passed by the familiar shape of the London black cab and walked off into the night.
CHAPTER 2
THE PUZZLE BOX
Tilly marched briskly past the row of office buildings, whose windows reflected the first rays of sunrise – which were not dissimilar to the orange tips of her hair, the remainder of which was currently dyed electric blue. Knightley