There’s nothing scarier than a health care professional that wants to kill you. From real-life mass murderers like Niels Högel to fictional butchers like Dr. Giggles, the thought of a doctor or a nurse intentionally harming their patients is deeply chilling. A new Argentine film from International Film Festival Rotterdam taps into these fears, and comes up with a mixed bag.

An icy medical thriller shot with heavy blue filters, Martin Kraut’s feature debut La Dosis introduces Marcos Roldán (Carlos Portaluppi), an nocturnal ICU nurse in his 50s whose life is thrown out of balance with the arrival of handsome young nurse Gabriel (Ignacio Rogers). The men share a dark secret related to their profession – they both like to euthanize patients, but for different reasons. Marcos does it out of pity, and Gabriel out of pleasure. As the bodies pile up and higher-ups at the hospital start to suspect something sinister, the two men form a toxic relationship that quickly spins out of control.

The setup is quite intriguing, but there’s something stagey about the execution – it feels a bit too talky for a thriller. There’s also a distinct lack of danger in the air. Rogers underplays the role and never feels quite unhinged enough to do something violent or erratic beyond killing bedridden patients. That alone is indeed quite frightening, but we know this from the get-go, and there’s no real escalation in behavior that ratchets up the tension. Sure, he manipulates the hell out of our protagonist, but he himself kills people without their consent, and this hardly produces any sympathy from the audience.

Naturally, a film about two male nurses should have a bit of homoerotic tension, and this certainly does. However, the sexuality of these characters is barely explored until 2/3 of the way through, and once some more information is revealed, it feels incredibly inconsequential. One wishes the script would exploit the gay villain aspect to its full potential and let him carry just a little more.

All these gripes aside, there’s something fascinating going on here, and the film remains perfectly watchable throughout its brief 90 minutes. Kraut maintains plenty of tension, but his script desperately needs a better third act. The inevitable showdown between the two men is incredibly brief and tidy, just as its resolution. The whole thing would be far more entertaining if it’d just lean a bit more into its trashy Lifetime thriller tendencies.

La Dosis premiered on Sunday at International Film Festival Rotterdam (IFFR)