Former Rainbow member Seung Ah is the voice behind the theme "Love Sick" for part 4 of MBC's 'Secrets and Lies' OST.

"Love Sick" is about asking your heart to erase everything from your painful heart, and it serves as the theme song for Seung Ah's character in the drama, Shin Hwa Kyung (otherwise known as Park Seon Joo), who's struggling to get through life and her ambitions.

Check out Seung Ah's "Love Sick" above! Have you been watching 'Secrets and Lies'?