I can’t bear it. I want to go back in time and put it all right. If only Sadie hadn’t married Waistcoat Guy. If only Stephen hadn’t gone to France. If only her parents had never caught them. If only-

No. Stop with the if-onlys. There’s no point. He’s long dead. She’s dead. The story’s over.

There’s a stream of people walking past me on their way to Waterloo station, but I don’t feel ready to go back to my little flat yet. I need some fresh air. I need a bit of perspective. I push my way past a group of tourists and head up to Waterloo Bridge. The last time I was here, the clouds were low and gray. Sadie was standing on the barricade. I was yelling desperately into the wind.

But this evening is warm and balmy. The Thames is blue, with only the tiniest white ruffles. A pleasure boat is cruising slowly along, and a couple of people are waving up at the London Eye.

I stop at the same place as before and gaze out toward Big Ben. But I’m not seeing anything properly. My mind feels lodged in the past. I keep seeing Stephen’s dated, scratchy writing. I keep hearing his old-fashioned phrases. I keep picturing him, sit ting on a clifftop in France, writing to Sadie. I even keep hearing snatches of Charleston music, as though a twenties band is playing

Hang on a minute.

A twenties band is playing.

I suddenly focus on the scene below me. A few hundred meters away in Jubilee Gardens, people are gathered on the big square of grass. A bandstand has been put up. A band is playing a jazzy dance number. People are dancing. Of course. It’s the jazz festival. The one they were leafleting about when I came here with Ed. The one I still have a ticket for, folded up in my purse.

For a moment I just stand there on the bridge, watching the scene. The band is playing the Charleston. Girls in twenties costumes are dancing on the stage, fringes and beads flashing back and forth. I can see bright eyes and twinkling feet and bobbing feathers. And suddenly, among the crowd, I see… I think I glimpse…

No.

For a moment I’m transfixed. Then, without allowing my brain to think what it’s trying to think, without letting a single hope flicker to life, I turn and start walking calmly along the bridge, down the steps. Somehow I force myself not to rush or run. I just move steadily toward the sound of the music, breathing hard, my hands clenched tight.

There’s a banner strung over the bandstand, silver balloons are gathered in bunches, and a trumpeter in a shiny waistcoat is on his feet, playing a tricky solo. All around, people are gathered, watching the Charleston dancers onstage, and on a wooden dance-floor laid on the grass, people are dancing themselves-some in jeans and some in so-called 1920s costumes. Everyone’s smiling admiringly and pointing at the costumes, but to me, they look rubbish. Even the flapper girls onstage. They’re just imitations, with fake feathers and plastic pearls and modern shoes and twenty-first-century makeup. They look nothing like the real thing. Nothing like a proper twenties girl. Nothing like-

And I stop dead, my heart in my throat. I was right.

She’s up by the bandstand, dancing her heart out. She’s in a pale yellow dress, with a matching band around her dark hair. She looks more wraithlike than ever. Her head is thrown back and her eyes are closed in concentration, and she looks as though she’s shutting out the world. People are dancing through her, trampling on her feet and elbowing her, but she doesn’t even seem to notice.

God knows what she’s been doing, these last few days.

As I watch, she disappears behind two laughing girls in denim jackets, and I feel a dart of panic. I can’t lose her again. Not after all this.

“Sadie!” I start pushing my way through the crowd. “Sa-die! It’s me, Lara!”

I catch a glimpse of her again, her eyes opened wide. She’s looking all around. She heard me.

“Sadie! Over here!” I’m waving frantically, and a few people turn to see who I’m yelling at.

Suddenly she sees me, and her whole body goes motionless. Her expression is unfathomable and, as I near her, I feel a sudden apprehension. Somehow my perspective on Sadie has changed over the past few days. She’s not just a girl. She’s not even just my guardian angel, if she ever was that. She’s a part of art history. She’s famous. And she doesn’t even know it.

“Sadie-” I break off helplessly. I don’t know where to start. “I’m so sorry. I’ve been looking everywhere for you-”

“Well, you can’t have looked very hard!” She’s busy scanning the band and appears totally unmoved by my appearance. In spite of myself, I feel a familiar indignation rising.

“I did! I’ve spent days searching, if you want to know! Calling, shouting, looking-you have no idea what I went through!”