The sudden disappearance of Sheung Wan's most beloved neighbourhood dog before Christmas caused much alarm and sadness. But the story has a happy ending, almost. A giant postcard (pictured) put up recently on a billboard in Jervois Street would have melted the most hardened soul. It turns out that Darkie, a 12-year-old black mutt, has taken up residence on the luxury estate Bel-Air, at Cyberport, after he was discovered to have late-stage thyroid cancer. The postcard says: 'Dear friends, don't worry about me. I am being taken good care of and feel much better these days. I hope to recover enough to visit all of you more often.' Darkie was raised by the operator of a waste-recycling shop in the Sheung Wan neighbourhood. But he collapsed last month. Neighbours pooled money to pay for a vet, who determined that the dog had terminal cancer. According to a neighbour, an investment adviser who used to run an office in the area found out about Darkie's condition. So she took the dog home to her luxury apartment and has been taking care of him. It was the investment adviser who posted the greeting card and took Darkie back to his old street to visit the neighbours last week, much to their delight. The street has a pet corner where people can post messages about animal welfare.