The Human Metal Detector first appeared in Wake the Devil as a new agent for the BPRD. His first mission placed him in Romania along with Elizabeth Sherman and Bud Waller. They end up discovering Roger in a hidden room and accidentally awaken him. Roger kills Bud and escapes, leaving Liz in a coma and Sidney badly burned.
Sidney discovered his ability in college, when he was completing his degree in mechanical engineering. He’s able to detect metals at a distance of several yards.
Sidney also appears in the animated series, voiced by Rob Paulsen, who’s known for voicing the characters Raphael, Yakko, and Pinky. He appeared in Blood and Iron, which was based on the Wake the Devil storyline.