As the Gatekeeper 's daughter , Clare was the only one who could undo the seal .
It was later revealed she was the heir to the role of the Gatekeeper , and that her mother had died using her powers to seal the Morlocks within the Underworld .
As the Gatekeeper 's daughter , heir was the only heir who could undo the seal .
It was later revealed she was the heir to the role of the Gatekeeper , and that her mother had died using her powers to seal the Morlocks within the Underworld .