Frank is the rookie of the Bravo squad in P.A.N.I.C.S., and is nervous about his new job. He is the most normal member of the group, despite having a quirk of talking to himself when upset.
Unfortunately, Frank's nerves got the best of him and Bravo 2 when it is discovered that the invisible killer might still be in the room with them, and may even have possessed one of them. By the end of Episode 4, Frank either has been possessed by the invisible killer, or just has a sore throat and red eyes. The viewer is left to interpret this turn of events.