"It's a pleasure to meet you, Miss….?"

"Malone," I replied. "Melody Malone. Likewise, Mr President."

I treated him to my best smile. It never fails. Well, it certainly had a knockout effect on JFK – though to be fair, the hallucinogenic lipstick may also have been a factor. And I like to think it played its part in helping that nice Mr Obama secure a second term. It didn't have much effect on Tricky Dicky, though in my defence, I was a little preoccupied at the time.

I returned my attention to the distinguished figure seated beside me. Franklin D Roosevelt, 32nd President of the United States. Seemed a nice chap.

"I'm sorry… it is Miss?" he went on. "Are you married?"

"Ah." I smiled again. "That, I'm afraid, is classified information."

I'm meant to be lying low. Hiding, if you like. And yes, I suppose gatecrashing a reception at the White House isn't the most immediately obvious way of doing that. But a girl gets bored, all alone in the big city. The big city in question being New York, 1938. The perfect hiding place – from one person, at least. I have my reasons.

And here I am in Washington. Luckily I have a useful little gadget that helps me get wherever – and whenever – I need to be with the minimum of fuss. I keep it well hidden, though. It would confuse people. To be perfectly honest, I think I confuse people enough simply by being me. It's just the way I am.

Anyway, I'd heard something about the White House. Something… odd. And I wanted to investigate. I am an investigator, after all.

"Melody Malone," I said again. "Proprietor and sole employee of the Angel Detective Agency in New York City."

"A gumshoe?" He raised an eyebrow. "I wouldn't have expected that."

FDR, president, reformer, survivor of childhood polio which had left him partially paralysed. The only president to serve more than two terms, although he hadn't yet. 1938, the eve of war in Europe. He did look a bit stressed.

He took a sip from his glass and I glanced around the room. My eye fell on a stone statue which stood in a recess. Nothing obviously remarkable about it, as statues go. A young woman, in flowing garments. With wings. I frowned slightly.

Suddenly the President turned pale and swayed slightly in his seat.

"Are you all right, Mr President?"

"I need a doctor," he gasped.

"Don't we all?" I quipped. But it was no time for jokes. I signalled for help and immediately half a dozen staff came hurrying over. I took the opportunity to slip away. Not that I wasn't concerned about the President – I'm not a complete psychopath, despite what some claim to believe – but he was clearly in good hands, and the chance was too good to miss.

I barely had time to glance at the stone angel as I hurried past, though a brief remembered pain flashed through one wrist. And another kind of pain, a less physical one.

But my self-control is iron. If I'm hurt, or frightened, or lonely, I know precisely how to never, ever let it show.

I learned that lesson early.

My heels tapped along the corridors as I tried to look as though I knew where I was going. I wasn't entirely sure what I was looking for, but I'd know it when I found it – if I got the chance.

"Excuse me, ma'am." A heavyset dark-haired man, in his 40s, hurried towards me. He stopped, looked at me with a kind of confused recognition. "I mean, Professor….."

"Melody Malone. Miss," I said briskly, cutting him off before he could say... whatever he'd been going to say. I had never seen him before in my life. Much further along the corridor, a slim figure turned a corner and disappeared into an office. I broke into a run.

As I pushed open the office door, the dark haired man was right behind me. I could hear more heavy footsteps approaching along the corridor – a lot more. Across the room, a young woman, her back turned, was rifling through a filing cabinet. The sober dark suit with calf-length skirt and modest heels was a far cry from the outfits I was used to seeing her wear, but the height and the sweep of glorious red hair were unmistakable.

"Mrs Williams…." The man behind me spoke.

She turned. She gasped.

My smile was genuine this time.

"Hello, Mum."