Arun Bose-directed Luca's initial conceit reminds us of Martin Prakkat's Charlie, a film that delves into the past of a mysterious artist, except that the titular character in the latter is a vagabond who vanishes from one place to another. But in the case of Luca, the titular protagonist is vanished forever, a dead man.

Luca is a whodunnit in which a bunch of cops led by Akbar investigates the mysterious death of Luca, a hot-headed artist with a problematic past. Upon searching his house, Akbar stumbles upon a diary that gives a key to Luca's past, which is associated with his lover Niharika Banerjee (played by Ahaana Krishna), a student. From the start, Luca does not delve much into the mechanics of investigation, the film gets sidetracked with a subplot involving Akbar's troubled marriage and his struggle to get over his old flame. The overbearing presence of inconsequential sequences really leads to some pacing issues in the film. The plot wanders a bit at these places.

The basic element of a procedural is the presence of suspicious characters so that there can be various possibilities of enhancing the element of mystery. Here, it is lacking, every unassuming character in Luca's backstory comes across as harmless. The film doesn't grip you at a point due to the lack of tension in the narrative. Hence Luca comes across as a mildly engaging fare at some levels.

But the film really picks its pace to an extent during the second half, where we get to see some shades of rebellion in him. He takes a risk and the stakes get higher at these moments. The film brings in some element of danger that is required for a thriller. One wishes that the film's romantic subplot involving Luca and Niharika could have been shortened a bit. But the film's third act really ties everything together with a fairly convincing end. You get to pick the pieces together to complete the puzzle, except that the pieces are not jumbled well, the film waters down its element of surprise through a lack of better characterization and a wafer-thin plot. But the end subtly conveys that an unhappy end of one love story can lead to a happy beginning of another.

Visually, Luca is an effectively atmospheric film. The film's faded, bluish colour palette beautifully complements with the rain-drenched setting. The interiors of Luca's house is crafted beautifully to create an artistic, Bohemian look (art direction is by Anees Nadodi). The film has some consistently good filmmaking, with well-staged moments (the scene involving a dead cat is a great example). With well-lit sequences and a terrific soundtrack by Sooraj S. Kurup, the flawed plot gets salvaged by a refreshing touch of lightness. Luca excels as a poignant mood piece where the visuals compensate for the plot. 

Ahaana Krishna and Tovino look really good together, and they give a spirited performance. The acting is wonderfully underplayed throughout the film. On the whole, Luca is a mediocre romantic tragedy that is uplifted by its picture-perfect filmmaking.