"Commissioner of Fear" is set anywhere from forty to fifty years after the events of the original story (depending on which reference you believe for the Beyond series). Barbara is now the commissioner of Gotham, pursuing a lowlife who has information on the kidnapping of a young girl.
Batman assists in the apprehension, but true to her portrayal in the animated series, Barbara rejects the help. Interrogating the criminal atop a roof, she suffers a flashback to the earlier fantasy.
Barbara's emotions swing wildly. She's terrified of the drop one second, willing to kill the punk to get the info she needs the next. She understands she must find the mobster Sweeny Thompson, but knows she's undergoing a periodic relapse of the fear toxin's effects. She turns to Batman for help, explaining that his predecessor Bruce Wayne devised a treatment years earlier.
Batman agrees to help, respecting Barbara's privacy enough to even keep Bruce Wayne in the dark. From there, he follows Barbara throughout Gotham, offering her support through the panic attacks, and ultimately sparing her life when the mobster tosses her from a high-story construction project. The child is saved, and Barbara reaffirms to Terry (as Bruce secretly eavesdrops) that he is truly the Batman now.
It's a solid idea for a sequel, and the summary paragraphs above make this sound like it had great potential as an actual Beyond episode. Barbara was criminally underused on that series, the concept of her carrying a grudge and earnestly looking to put Batman in jail simply lost along the way. Having Batman win her over while working a case, and closing an episode with the declaration that Terry is the true Batman now would seem to be a perfect season finale.
"Commissioner of Fear," however, has serious problems. Like many issues of the series, the execution feels rushed. There's an effective use of a montage sequence, but many other scenes really do require a slower pace. And Barbara's mental state is rarely convincing, often due to some clumsy transitions. What the heck is happening between these last two panels?
Also, as a Barbara story, allowing Batman to swoop in at the end and rescue her seems debatable. Since it's a story about Barbara conquering her fear, shouldn't the climax grant her a personal victory? Batman flying in to save her might be fine in an average story. Here, it feels as if Barbara is accomplishing almost nothing, yet it's her spotlight tale.