Via AJ:

It reads like a mystery novel.

"The art experts climbed four flights of stairs in a dingy block of flats in the north-west of Spain, with dwindling hopes."

When they met the old man who had responded to the Christie's ad, "He went off to hunt in a cupboard in another room, and fetch the proverbial brown envelope - and out of it came this wonderful thing."

It was an original painting by El Greco!

Read The Guardian story here.