Sizzling-hot sex, compelling characters, humor and a dual plot make Primal Instincts (4.5), by Jill Monroe, a book you can't put down. Publisher Miriam Cole has a passionate one-night stand with young Jeremy Kelso on a business trip. She doesn't plan to see him again and is shocked that he wants to take their relationship further. Meanwhile, Miriam sends her reporter brother Ian to meet the anthropologist whose book she wants to publish. That's how he finds beautiful Ava Simms, who knows more about sex in primitive cultures than in modern America. Watching both use what they know of sex to seduce the other is very funny and hot. Will brother and sister learn that opposites can not only attract but find true happiness?