|“||Dear Suze, You saved my life. I know you don’t believe it, but you did. If you hadn’t done what you did for me, I would still be afraid. I don’t think I will ever be afraid again.||”|
— Jack's letter to Suze, Darkest Hour
Jack Slater is an eight year old kid who had only realized his mediator ability when Susannah Simon (or Suze, as she wanted to be called) had talked to him out of it. He didn't like swimming, or bike riding, or Rollerblading, or Frisbee tossing, or anything that has to do with outdoors. He used to be afraid of walking outside– in which Suze personally finds it weird –because he sees ghosts, and he feared that no one would understand him. Not until he helped her solve the problem of the recently-died gardener of the hotel, Jorge. His fear of going outside vanquished as he became more proud of his mediating ability.
Because he was only young and didn't know about Jesse, he was tricked into exorcising him without Susannah's consent. Upsetting her, he tried helping her when trying to retrieve Jesse's soul from the purgatory but was stopped when another mediator Father Dominic found the two and persuaded that they would do a proper exorcism in a church. And of course, without Jack helping them. He later appeared again in the Mission School church and insisted on helping Suze. He was then given a permission by being assigned a task that, if she hasn't retrieved Jesse in twenty-five minutes, he would pull the rope attached to Suze's waist so she would return back to her body again. However, some time later, Maria de Silva and Felix Diego showed up and attempted to cut the rope so Suze would be stuck in the purgatory forever. Even though succeeding, Jack went into the hole to search for her. When he did, his brother Paul emerged, and then proved that he was something else.
After the happening and after retrieving Suze and Jesse's soul, Jack returned to the hotel. The day after that, the Slaters checked out and gave Susannah an envelope containing $200, as a tip. She also received one from Jack, only with not money, but a miniature of Jesse de Silva that they had seen in a historical society.