Mark comes to the Teen Team with new information; the school disappearances are connected with the recent mall bombings. However, they're still not sure who's behind the destruction so Robot sends them all home. The next day, Robot alerts Mark that he's found a connection between the mall bombings and one of the teachers at his school-- Mr. Hiles is a former weapons engineer. Eve and Mark descend upon his home, where he's been waiting for them. Once inside his home, he tries to blow himself up to kill both Eve and Mark. But Mark saves the day, flying as fast as he can out of the city so that the teacher can explode where no one will be hurt.
Later on Mark's dad returns from the alien dimension.