US TV
Rex Features
According to TV Guide, the 27-year-old will play a cancer patient called Lucy Morton, who has lost all her hair from treatment.
Moss begins shooting her scenes - most of which are said to be with Taylor Schilling's Veronica - on Friday in a New Jersey hospital and her episode is slated to air November 4 on NBC.
Mercy recently debuted to 8.25m viewers, beating all other competition in its timeslot.
> Schilling: 'Mercy differs from Grey's'
Tube Talk
The Best TV Couples: Friday FiverTube Talk celebrates Valentine's Day by reminiscing about the best TV couples.
2012-13 Season
John Stamos to star in 'Little Brother'The former Full House actor will star in the comedy pilot Little Brother.
US TV Interviews
'Celebrity Apprentice' Donald Trump Q&ADonald Trump teases the new season of Celebrity Apprentice.
US TV Ratings
'Vampire Diaries' soars to 3m for The CWThe Vampire Diaries and The Secret Circle perform well for The CW.
