Which type of figurative language is in the phrase, "in over his head"?

(99 ! ) read the excerpt from the monsters are due on maple street. mrs. goodman that's exactly what he does. why this whole thing it's . . it's some kind of madness or something. steve (nods grimly) that's exactly what it is—some kind of madness. charlie's voice (shrill, from across the street) you best watch who you're seen with, steve! until we get this all straightened out, you ain't exactly above suspicion yourself. steve (whirling around toward him) or you, charlie. or any of us, it seems. from age eight on up! woman one what i'd like to know is—what are we gonna do? just stand around here all night? charlie there's nothin' else we can do! (he turns back, looking toward steve and goodman again.) one of 'em'll tip their hand. they got to. 57. continued 57. steve (raising his voice) there's something you can do, charlie. you could go home and keep your mouth shut. you could quit strutting around like a self-appointed hanging judge and just climb into bed and forget it. what do steve’s reactions to mrs. goodman and charlie show the reader about steve? steve is frightened of the alien invasion. steve is an alien in disguise. steve does not like many of his neighbors. steve is sensible and unafraid.