Their relationship started and in Loner. Zachary started to talk to Cassie because he realized she looked like his old friend Amelia. However, while he was sorry to hear her mother was dead, he quickly became angry over the fact she was staying as he realized her presence completed the Chance Harbor Circle. When he realized she knew she was a witch he became determined in breaking the Circle to ensure another magical massacre did not occur.
He went to the school dance to kill Cassie, partly to get revenge because her mother doomed his girlfriend to a fate worse than death, but his assasination attempt was foiled by the Circle. Unknown to the Circle members, Dawn and Charles kidnapped Zachary and marked him as one final warning to never come close their children again.