This is the grave of the man who died of food poisoning six months before his wife baked an ‘arsenic-laced’ Christmas cake that killed three of her relatives. But within hours of tucking in, her sisters Maida Bernice Flores da Silva, 58, and Neuza Denize Silva Dos Anjos, 65, and Neuza’s daughter Tatiana Silvia Dos Santos, 43, were all dead …