A theories → Wren Kim/Kingston
1x01 Pilot: Wren gives Spencer a massage to relieve the fluid build up in her bursa sac. It becomes clear Wren was good at this.
2x10 Touched by an A-ngel: Emily receives a massage from A and doesn’t even notice that the person giving her a massage isn’t a professional. Coincidentally, Wren is good at giving massages.
1x11 Moments Later: Hanna’s received an A message while she was in the hospital, surely she’d have taken note of what her school friends were writing on her cast. Wren works in the hospital and could have checked on her, found she was sleeping and wrote the message then.
2x8 Save The Date: Emily receives an A message while in the hospital on the lid of her coffee. The coffee is served by the staff at the hospital Wren works at. Wren is also one of the doctors taking care of Emily and also delivered the news about the human growth hormone found in her body. Wren is a med school graduate, so would know how HGH can affect someones athletic performance and would know how to inject it into foods or creams.
1x11 Moments Later: The tree with Alison + Ian carved into it is burned in a fireplace at the end of this episode and a spear thing is used to poke at the wood. At this point Wren is sleeping on a friend’s sofa after being kicked out of the Hastings’ house for cheating on Melissa.
2x21 Breaking the Code: The same spear things are propped up next to the fireplace at Wren’s new house. Maybe the spear things belonged to him and he just use them at the friend’s house to help burn the wood quickly and now he has them for decoration around the fireplace in his new home.
2x16 Let the Water Hold Me Down: The receipt Spencer finds in her lake house is from a newsstand in Philadelphia, where Wren lives. The receipt is only for magazines and gum and no one travels all the way into the city for just magazines and gum, they’d go to the local convenience store. However this would be the local convenience store for Wren.
2x24 If These Dolls Could Talk: Again, the doll shop is close to where Wren lives. The child in the doll shop told the girls that it was a guy and a girl who bought the voodoo doll to send to Alison and that those who bought it wanted to hurt her. Melissa has made it obvious that she hated Alison, and buying the dolls are a convenience to Wren as he lives not far from the doll shop and could get there quickly in the middle of the night. When A pulled the “Follow me, end up like me” prank, Wren would have been able to get in and out of the shop and get back to his house quickly without Spencer and the girls seeing him or arising suspicion.