‘Where are we going?’

‘Downstairs.’

‘But They can’t get in…’

The Crow frowned. ‘Well, something’s giving me the shivers. Follow me. And keep quiet!’

Plas-y-Fran was sleeping peacefully. There was no fairy music here, no danger. The white corridor with its cabinets of china and old portraits stretched out into dimness, slanted by shafts of moonlight from the high windows.

The Crow swooped away. Sighing, Seren hurried after it. This was such a fuss over nothing! They were safely outside, and the house was guarded by all Denzil’s horseshoes and hanging magic herbs. Everyone knew the Tylwyth Teg couldn’t get past such a strong defence.

Then something Denzil said came back to her with a shiver.

Unless They were invited.

She ran silently after the Crow to the landing and crept down the main stairs, the bannister curving in the dimness under the portraits of long-dead Joneses. She glanced up at their pale faces, the ladies with hair piled high and the gentlemen with guns and dogs. They watched her go by. The Joneses were her family now. But sometimes she wondered if the people in the portraits were thinking Who is that little girl in the nightdress? And why is she here, in our house?

She bumped into a vase on a pedestal and grabbed it hastily before it fell.

The Crow tutted. ‘What is the matter with you! Don’t make so much noise!’ It sniffed the air, turning its moth-eaten head this way and that. ‘Definitely a whiff of spell somewhere. The library, maybe.’

They tiptoed over the dark creaky floorboards. At the library door Seren turned the handle and opened the door a tiny crack. She peeped in.

Everything seemed to be quiet, so she slid inside. The Crow flapped after her.

The huge bookshelves reached up to the ceiling, their gilt spines enticing; all their enchanting volumes of story closed and asleep.

But the curtains, usually shut tight at night, were drawn back, so that moonlight lit the room. Seren held the candle up, though she hardly needed it. And then she saw something impossible.

On the table in the centre of the room a green pen was writing.

All by itself!

It was scribbling elegant names on a pile of cream stationary. Seren recognised the gold letters of Lady Mair’s invitations. The invitations to the Midsummer Ball!

‘What on earth…!’ the Crow gasped.

As if it heard, the pen gave a jump and scribbled faster. They saw that as each invitation was written it folded itself up and became a creamy paper bat. Hundreds of them were flitting out of the window, an outpouring of invitations.

The Crow gave a squawk of horror.

‘Get that pen! NOW!’

Seren had to put the candle down carefully but then she made a dive at the table. The pen leapt into the air, ink splashing from the open inkwell; it dived under the pile of papers but Seren flung them aside and grabbed it, feeling the greenness of it squirm in her fingers.