The former "Taxi" cast member will appear on a November episode of "Unforgettable." She is to play Edie Tripp, aunt of Carrie Wells, played by Poppy Montgomery, and sister of Carrie's Alzheimer's-stricken mother, Alice, played by Deanna Dunagan.
"Carrie and Edie have a strained relationship, disagreeing over the years about Alice's treatment, and when Edie begins experiencing memory issues of her own, Carrie voices concern about her aunt possibly also exhibiting the signs of Alzheimer's," CBS said in a synopsis.
Henner is one of the few people who possesses the recently-discovered ability of Highly Superior Autobiographical Memory, which means she can recall details from almost every day of her life, the network noted. She also serves as a consultant for the series about Carrie, a young woman with the same ability.