How Did Deanna Troi Son Die?

How Did Deanna Troi Son Die? In 2379, Troi transferred to the USS Titan (Star Trek: The Next Generation; Star Trek Nemesis). By 2399, she and her husband William T. Riker lived on the planet Nepenthe with their daughter, Kestra Troi-Riker. Their son, Thaddeus Troi-Riker, died of Mendaxic neurosclerosis soon after their arrival on Nepenthe.