Rise: Blood Hunter

Reporter Sadie Blake has just published a notable article featuring a secret Gothic party scene. The very night following the publication, one of Sadie's sources, Tricia Rawlins, is invited by her friend Kaitlyn to an isolated house in which such a party is to take place. Tricia is reluctant to enter with the curfew set by her strict father, so Kaitlyn goes alone. When she does not return, Tricia becomes worried and enters the house as well. To her horror, she finds Kaitlyn in the basement with two vampires hanging onto her and drinking her blood. She tries to hide, but the vampires find her quickly. The next day, Sadie learns of the girl's death and decides to investigate the matter. She soon attracts the interest of the vampire cult, who kidnap her and bring her in for questioning. Following that, she is raped and murdered by the vampires.
To her surprise, Sadie abruptly awakes inside the cold box of a morgue. She escapes, but in the course of the following hours she finds to her horror that she has turned into a vampire herself. After wandering the streets she ends up in a homeless shelter where she soon gives in to temptation and kills an old sick man and begins to drink his blood. She then runs out of the shelter when a young girl notices her causing her to break down. She attempts suicide by throwing herself off a bridge, but is found and taken in by fellow vampire Arturo who is less blood-thirsty and more benevolent than his brethren. Though his true motives are unclear â a power struggle between Arturo and the leader of Sadie's killers, Bishop, is mentioned â he helps Sadie to cope with her new condition and trains her to fight when she announces her intent to get revenge on her murderers.
Sadie tracks the vampires across the state, killing them one by one, while at the same time fighting the urge to consume blood from human victims. She soon crosses paths with Detective Clyde Rawlins, Tricia's father, who has taken upon himself to avenge his daughter's death despite the objections of his superiors and colleagues. At first he takes Sadie for an enemy, but in time he recognizes that she is not of the same breed as Tricia's killers, and they team up in their pursuit of Bishop, the last survivor of the band. They track him to an abandoned stable complex, where they find not only Bishop but also Tricia, now a vampire, who openly voices her resentment and anger for her father. A hard fight ensues in which the evil vampires temporarily gain the upper hand. Along with two other women, Sadie is stripped naked and suspended by her ankles, with her wrists bound behind her back, to slowly drip blood. She is saved by Rawlins. The pair then turn the table against their enemies.
After Tricia and Bishop are killed, Sadie asks Rawlins to kill her too. She cannot bear the thought of having to give in to her bloodthirst and that she, since she is already dead, can never see her mother and sister again. Reluctantly, Rawlins grants her request and stabs her with a silver crossbow bolt. Once again, Sadie's body ends up in the morgue, but we see her come back to "life" again once more as the end credits begin to roll.

Question: Who abruptly awakes inside the cold box of a morgue?
Answer: Sadie.