Isla was a criminal organization which operated illegal fish trade in New York in the 1920s. Known for their initially peaceful approach, Isla became increasingly more violent and ruthless with years, culminating in a series of killings at the end of the 1920s, which primarily targeted private investigators. Subsequent coverup murders led to the evisceration of the fish trading community, as many people working in fish markets, as well as many fish producers, had been murdered as well. Isla's boss Tirsa Herrero was then murdered by her own underlings who then fled New York and Isla was thus dissolved.