This was an interesting movie right up until the moment we learn who Liam really is. At that point, we're expected to believe that not only did this inexplicable cosmic event afflict him with his terrible power, (and tie it to his planned next victim) but that it also completely changed his personality from homicidal monster to decent, caring, and self-sacrificing.
The magic space zap is something I can suspend my disbelief over, because it sets up an intriguing mystery and character study. Evil to good at the flip of a switch is far less believable, especially since they had another, more interesting story sitting right there with Jane/Rose's husband. The tension in their relationship actually makes sense if he's the killer. The unfolding movie is then about Jane solving the mystery of her missing sister and also allows for Liam's sacrifice to be both believable and to have more emotional weight.
Real missed opportunity.
The magic space zap is something I can suspend my disbelief over, because it sets up an intriguing mystery and character study. Evil to good at the flip of a switch is far less believable, especially since they had another, more interesting story sitting right there with Jane/Rose's husband. The tension in their relationship actually makes sense if he's the killer. The unfolding movie is then about Jane solving the mystery of her missing sister and also allows for Liam's sacrifice to be both believable and to have more emotional weight.
Real missed opportunity.