A young amateur keyboardist named Jon lucks his way into a temporary gig with a local band in need of a replacement. He tweets about it excitedly as the hour arrives, only to find his fellow bandmates a little less than welcoming. .As they begin to play, a tall, angular man wearing an oversized plaster head strides to center stage and plugs a microphone cable into a jack dangling from the neck hole of his mask. He proceeds to rant and rave as the music intensifies, the sound breaking out to a plateau of melody that begins to sound quite beautiful. The beauty does not last, as one of the amps blows, causing the theremin player to storm off in a huff. As quickly as it began, the concert collapses on itself, and Jon is left bemused, standing next to this oddity with a head that looks like the intersection of the Bob’s Big Boy mascot and Mr. Bill from those bizarre Saturday Night Live skits from the 70’s. His name is Frank.

Frank appears to see something in Jon, and conscripts him to be the band’s full time keyboardist just as they are about to embark on recording their newest album. Suddenly, he finds himself in a remote wooded group of cabins surrounded by the unhinged Clara (the woman who disrupted the gig), a guitarist and drummer who appear to only know French, and a man who will not take his giant mask off under any circumstances. The group is volatile to say the least, and has not managed to record a single note before the money runs out. Jon breaks into his nest egg to keep them going and begins documenting the experience via various social media outlets. The wild, often violent escapades of the band foment a miniscule cult following, and the buzz lands them a gig at SXSW. Everyone else balks at the idea except Frank, who relishes the opportunity to reach a wider audience. As they descend on Austin, the band discovers they may not be as popular as their YouTube hits might have indicated.

Domhnall Gleeson plays the role of the hapless sycophant Jon, the sort of man who tweets his every movement, complete with obnoxious hashtags. He has no clue just how in over his head he is as he travels into the forest to record with Frank, and it is clear that while he has some baseline talent for playing the keys, he is devoid of even the remotest scent of creativity when it comes to, well, anything. Jon is infuriating, but this is by design after all,and from that perspective he is effective at his role. In taking on the part of Frank, Michael Fassbender disarms by hiding his most recognizable asset, his intense face and steely eyes. He further subverts expectation because Frank is a comedy. It is a side of Fassbender that has been seen in small doses, but never with such unbridled verve. He slips into the comedic without breaking a sweat, proving his preternatural talents could be applied in any situation. Limited to his body and voice, Fassbender makes Frank leap off the screen. Also strong is Maggie Gyllenhaal’s Clara, the most combustible element of the triad, with her matter-of-fact approach and her dead eyes.

The leads are accomplished and the characters intriguing. Yet in practice, Frank appears to be less than the sum of its parts. The promise of the first act is largely undone by its leisurely middle section, As the band leaves to record their record, director Lenny Abrahamson and his screenwriters Jon Ronson and Peter Straughan lean too hard on the fish out of water storyline and the quirkiness of the characters, making the final product paper thin. Things do not get particularly better when they arrive in Austin for SXSW, treading similar paths as other dysfunctional music movies or documentaries. The filmmakers may think that the oddity of Frank and the subversion of a strong protagonist in Jon, but these changes to the form do not provide enough spice to overcome the familiarity of the story.

There is a silver lining, which can be found in Frank’s final scene. A turn in the story happens in the third act that does not entirely work. The film relies on mental illness as a crutch in such a way that feels like a cheap out to explain away much of the interest in its characters. But it is all working toward a greater goal, one last chance at reinforcing the film’s narrative themes of the search for creative expression no matter the cost. It ends with a song, a beautiful and heartfelt one. It manages to crystallize the themes of the film and touch the heart. It is also the most accomplished piece of music of the entire film. But the question remains whether a quality ending can overcome past transgressions in the body of the film. In the case of Frank, it is a bit of a yes and no situation. While the final scene (which is one of Fassbender’s best) may send the audience out of the theater happy, it does not take long for that overly precious glacially slow second act to flow back into the mind. The final scene combined with the general oddity of the enterprise makes it worthy for a look, but its flaws outweigh its interest in the end.