House of the Mystery Hat

Most odd - but can you find this window?

Location: Goldhawk Road, W1

Description: And we quote from the author...

'I cycle past this building on the Goldhawk Road everyday. There is no sign above the door and no one ever seems to go in or out.

'I've no idea whether it's a hat shop, someone's house or some sort of secret organisation with funny handshakes, millinery passwords and impeccable head dress sense...

'Sometimes in the evening, a light comes on and the hat becomes a lampshade.

Other nights, it's all dark.

'I'm considering setting up vigil in the cafe opposite.

Partly to see who comes in and out.

Mainly to see if you get a badge when you join SSH'.

OUTSTANDING - but what number is it on Goldhawk Road?