This is book #3 of the Doris Fein Mystery series. I'm re-reading the entire series. I love them!
Carl Suzuki, Doris' Japanese-American friend whom she first met as a cop in New york City, is now a lawyer and he comes to the west coast to visit Doris. Doris' elderly millionaire friend Harry Grubb takes the two on a trip on his yacht to Catarina Island, off the coast of San Francisco. They dance and dine at the historic Casino on the island, where big bands once played. But now the Casino has been experiencing one mysterious accident after another. Locals blame it on a “Phantom”. Doris is there for two first-hand dangerous accidents. The middle of the story goes a bit slowly but the ending is exciting enough and I was rather surprised by the identity of the perpetrator of the crimes! Although Doris and Carl declare their love for each other, Doris decides that she must finish college and be her own woman before she can be anything else.