The story concerns a young boy called Juston Seyfert who finds and befriends a mutant-hunting Sentinel robot.

Despite featuring a different style to most of the company's other work at that point and some uncharacteristic story ideas, Sentinel and its fellow Tsunami titles were still part of the Marvel Universe.

Sean McKeever was considered a rising star in the industry at the time by Marvel editor-in-chief Joe Quesada.

Art duties were handled by Udon Studios; Eric Vedder, Joe Vriens and Scott Hepburn worked on the series.

He lives with his younger brother Chris and his father Peter, who operates a junkyard adjacent to their house; his mother walked out on the family years ago.

Being poor, Juston must find his own fun, and spends the days playing in the salvage yard or constructing robots from spare parts.

Initially frightened by the discovery, he begins to assist the rebuilding from scrap metal and reprogramming it; the two form something of a bond.

[10] The next day, Jessie tries to find Juston to talk with him when the Sentinel arrives and begins attacking the school, targeting the two bullies specifically.

It is later revealed that Juston staged the entire attack to earn positive standing at school and in the community, but he begins to feel guilt for the physical and psychological repercussions of his actions.

Juston's search for his mother leads him to an estranged aunt named Ginny Baker, who allows him in only with the hope that she be repaid with money that he received from all his media appearances following his "heroics" at the school from the previous volume.

[21] In an interview with McKeever for Newsarama, Matt Brady noted the series received good reviews but poor sales.