>Twenty years ago, seven detective-story fans formed a little group called the Seven Unravellers. A London bobby, a solicitor's clerk, a baronet, an ex-Army major, a greengrocer's daughter, a chemistry student, and a bohemian eccentric. They were as mixed a bag as any group of genuine murder suspects. But they had one thing in common: murder. Not the fact but the fiction of it. Once every month they met to discuss, and possibly solve, the latest crimes in murder fiction. >Now the Unravellers are together again, linked by the bizarre murders of three of their members - one of the deaths is the classic "locked-room" mystery in reverse. >The series of clues left behind are as puzzling as the crimes themselves. Each is related to one of the colors of the spectrum - the red dye in the sea near one member's home, the orange thrown through the window of another's office, a page from the post office's Yellow Pages pinned to a third member's door. At the first sign of trouble, amateur detective Thackeray Quin is called in. >*Invisible Green* is a brilliant detective story in the classical mold, but with a puzzle to tax the most up-to-date minds. John Sladek's plotting is precise, his suspects and victims from the dotty old Major to the surly ex-policeman and the trendy art director eccentric and entertaining, and the mystery highly ingenious.