Darren Wilden: It is revealed in the season four premiere by a tape of Mona's that Wilden was one of the Queen of Hearts on the Halloween Train. It is unknown if he was blackmailed into helping the A-Team or not. CeCe later killed him to protect Alison.
Melissa Hastings: In the fourth season she revealed to Spencer that she took orders from Wilden, because she was afraid of him and so she could protect Spencer, She was the Black Swan and also one of the Queen of Hearts on the Halloween Train. When Wilden died, she stopped helping the A-Team.