Actress L Scott Caldwell, who played Rose Nadler in 'Lost', is to guest-star in 'Grey's Anatomy'.
TVLine.com says Caldwell will play the wife of a patient who is participating in an Alzheimer's clinical trial that Doctor Derek Shepherd (Patrick Dempsey) is in charge of.
The episode is due to air on American television on 23 February.
'Grey's Anatomy' continues on Tuesday nights on RTÉ Two.
