It felt as if everything was against me – even the weather. As I made my way down to Stonegate, the cold rain ran down my legs and soaked through my socks and shoes. I hadn’t stopped thinking about my mother’s letter. In the light of my new suspicions about Mags, Mutti’s words about loving us, and asking us to be sensible felt strangely weighted. Did she believe that Mags was up to something? Could my sister really be the spy? Was that why Mags had been so keen to shift attention on to Spooky Joe? The disloyal thoughts hit me swiftly, one after another, like punches in the stomach. I had never felt so adrift, so alone. And the only person I wanted to talk to about all of this was the only person I couldn’t talk to.

When you share a room with a sibling, storms in teacups are never just storms – they are tempests. Every little quarrel is more cruel and more intense than it would be otherwise, and this was something much more serious than a quarrel. When I thought about going to bed that night, I was filled with dread – I could already feel that cold, electric tension, crackling in the silence between our two beds.

Thunder. I turned my head sharply towards the sea as a booming noise quivered over the grey water. It boomed again – a terrible blast of sound. Sometimes thunder sounds like an explosion in the sky, I thought, but that was usually when a storm was right overhead, and there hadn’t been any lightning yet. I walked more quickly, scampering down the path. If there was going to be lightning, I didn’t want to be the idiot standing out on the clifftop holding a big umbrella.

The high street was deserted. Everyone else was being sensible – sheltering from the storm inside their nice, cosy houses. I’ll just get to the bakery, I thought, and perhaps Mrs Rossi will be kind enough to offer me a cup of tea and a biscuit while we wait for the rain to stop.

But I didn’t get that far.

As I was going past Mrs Baron’s house, the glossy black door opened and a man came out. It must have startled me, I think, because I instinctively stopped and shrank back. Water from the gutter above splashed down on to my umbrella. I moved closer against the wall and watched as the door closed behind the man and he opened a black umbrella of his own. Then he clanked through the gate and set off down the high street towards the harbour. It was Pinstripe, the police detective. Visiting Mrs Baron, I thought, to talk about the spying investigation. They must have been discussing my Mutti.