“Possessor”, the second feature film by director/writer Brandon Cronenberg, is an oddly unnerving SF psychological thriller film which constantly disturbs us from the beginning to the end. While there are a number of gruesome moments which will definitely make you wince more than once for good reasons, the movie firmly sticks to its clinical attitude as steadily generating the uneasy suspense over matters of body and mind, and some of its highlights will linger on your mind for a long time regardless of whether you like it or not in the end.

After the opening sequence which strikingly ends with a bloody act of killing, the movie gradually lets us gather its science fiction setting. Its heroine Tasya Vos (Andrea Riseborough) has worked as an assassin for some shadowy agency, and the agency has depended a lot on a certain highly advanced neurological technology for executing those assassination missions without leaving any possible trace. All she has to do is subjecting herself to a special equipment which will transfer her consciousness to a chosen target which has already been implanted with a tiny transmitter, and then the target in question, who is totally under her mind control from that point, will carry out her assassination mission.

For not drawing any suspicion during her mission, Vos always has to prepare a lot in advance for perfectly imitating her target, and it is apparent from her weary face that her dirty, difficult, and dangerous job has taken a toll on her these days. When she visits her estranged ex-husband and their little son at one point early in the story, she has to practice a bit for reminding herself of who she really is, and her direct boss Girder (Jennifer Jason Leigh), who was also an assassination agent some time ago, shows reasonable concerns over her increasingly unstable state of mind. The latest psychological test on Vos does not show anything particularly serious for now, but Girder notices how Vos executed her recent missions more violently than usual, and Vos becomes less sure about whether she can continue to kill people as before.

And then there comes the latest mission for her. The person to be assassinated is the owner of some big corporation and his daughter, and the target to be mind-controlled by Vos is a guy named Colin Tate (Christopher Abbott), a pathetic loser who is incidentally married to that person’s daughter. Once that person and her daughter are eliminated, that person’s son will instantly inherit everything, and that will surely lead to the end of that corporation, which is exactly what is wanted by those unknown clients who ordered this assassination.

Once Tate is captured and then prepared for the transfer of Vos’ consciousness, the movie serves us a psychedelic scene which vividly conveys to us how confusing and grueling the process is to her. She successfully occupies her target’s body as planned, but it still takes some time for her to get accustomed to his body. Of course, his wife initially notices something different from her husband right from the beginning, but she simply disregards that without much thought, and Vos keeps sticking to her camouflage as waiting for the time to carry about her mission.

What eventually happens next will not surprise you much, but I assure you that Cronenberg and his crew members will jolt you hard via their cold but undeniably effective delivery of violence and blood on the screen. Like his director father David Cronenberg, he does know how to depict violence and mayhem with maximum dramatic effect, and the overall result is quite visceral and disturbing to say the least.

In the meantime, the movie also delves into the tricky realms of mind as Vos gradually comes to lose her control over Tate’s mind later in the story. As her mind finds herself getting more tangled with Tate’s mind, the movie attempts to depict their psychological conflict via a series of nightmarish images, and I was surprised to learn later that many of these boldly hallucinatory images were actually created via practical effects.

Above all, the movie works because of how its two main performers are flawlessly intertwined with each other in their acting. While she does not appear that much throughout the film, Andrea Riseborough’s haunting performance as a woman who becomes more rattled by her occupational hazard sets the solid ground for Christopher Abbott’s equally commendable performance, and it is compelling to watch how Abbott deftly channels Riseborough’s presence even when her character is nearly losing the control on his character.

It is a shame that two other notable cast members in the film are not utilized that much on the whole. Jennifer Jason Leigh does as much as she can do with her limited supporting role, and I enjoyed the subtle tension between her and Riseborough during their few scenes in the movie. In contrast, Sean Bean is merely required to be obnoxious during his brief appearance, but you will not be disappointed if you still remember that famous online joke on how often he has been brutalized on the screen for many years.

Although it is sometimes a bit too dry and abstract to entertain me, “Possessor” intrigues me with its science fiction story premise, and Cronenberg, who previously made a feature film debut with “Antiviral” (2012), did a competent job of handling its interesting ideas. He surely shows here that he has his own territory to explore right next to his father’s, and we will probably see whether he will advance as well as his father during next several years.