Selvan

The Selvan first attempted to take control of Lisa Beck's body directly by invading her dreams. Beck was able to repel the effort, forcing the Selvan to take another path. Using Walter Morales' feelings for Beck and his jealousy of Phillip Harper as a doorway, the Selvan took control of Morales, murdered Harper, and forced Beck to allow the Selvan to take over her body. (Dream Sequence, A Door Is Ajar [WAY])