Jack - Everybody's Big Brother played by Patrick Levis
Jack Phillips is two years older than his little sister, Fiona, which makes him fifteen in the first season. He's been the "man of the house" since his father, Rick, died and he seems to take the role very seriously. Despite his nearly constant ridicule of Fi's paranormal interests, he's always the first one out the door when Fi vanishes on one of her adventures and the first to blame himself when something goes wrong. He's also rather protective of their mother. When Fi creates a scene, problem, etc. and Molly sighs wearily before setting off to fix, lecture, etc. Jack frequently volunteers to step in. While Fiona makes friends, Jack seems to make "siblings". Despite his initial wariness when it comes to Fi's more... unusual acquaintances Jack's protective, big brother instincts can't help kicking in eventually. This trait is most obvious in "Tulpa" with James and in "Nightmare" with Danny. In Danny's case, he's even the one to solve the "paranormal problem". Although Fi leaves both these troubled youngsters with promises of friendship, it's Jack who leaves them with something of a role model - someone to look up to.
There are the occasional bonding moments between Jack and Fi, but not enough to be overly sappy and plenty of sibling battery and verbal abuse to make up for it. Emotions aren't Jack's strong suit. Expressions of emotion by either his sister or his mother seem to embarrass or otherwise upset him. In his role as "man of the house" he seems to think that showing his feelings, especially those dealing with his father, would be seen as weakness. He projects a strong front for Molly and Fiona... but occasionally it does crumble. Or at least crack. Brief glimpses of his true feelings are often expressed in sheepish statements of fewer than a dozen words apiece or, in some instances, even silently.
Jack's "X-Files" role is the Scully to Fiona's Mulder. He offers practical explanations to her more bizarre encounters despite the fact that, like Scully, he is frequently smack in the middle of events. Undoubtedly, he thinks he's protecting her from ridicule from "outsiders" who might not understand her. Better to be shot down by someone who loves you than someone who doesn't even know you seems to be his line of reasoning. He does realize that Fi's interest in the supernatural is directly related to the loss of their father and in his own way, he's trying to protect her from disappointment.