Oh, “Absentia.” This 10-episode thriller opens with two captivating back-to-back installments. The premise is as dramatic as they come. Emily Byrne (Stana Katic) is a wife, mother, and FBI agent, who disappeared chasing a serial killer. She has been missing for six years when she is found clinging to life in a tank filled with water. Her husband, a fellow FBI agent, is the one who finds her.