While organizing a neighborhood watch association to deal with a local vandal, Aidan ends up catching the attention of a police officer who is the son of a man he killed in the past.
Rebecca later acts on Bishop's order to sway Aidan's thoughts on her by sending him a DVD where she has sex with a man before draining him dry of blood.
Later that night, saving the house and Sally from a fire set by Danny, Aidan is almost staked in the heart by Bishop when he crashes through their living room window.
Aidan refuses, knowing he will bleed Cecilia dry, and ends up at a bar where he meets Julia, a new doctor hired by Suffolk County Hospital, and begins an intimate relationship with her.
Though Aidan feels a buzz after drinking, he starts convulsing in pain from the werewolf blood, vomiting and letting out an earsplitting scream that manages to snap Sally out of it.
However, when Mother comes to Boston to congratulate the two on fulfilling their duties, Aidan learns his freedom is actually an excommunication from vampire society under penalty of death.
Eventually Aidan resumes his job at the hospital where he meets Kenneth, or Kenny, a teenage boy who has Severe Combined Immunodeficiency Disorder and must live within an airtight chamber.
Later that day, she uses her poltergeist powers to enact revenge on Danny, wrecking his apartment and leaving a spiral of debris in the middle of the room, ending with her ring.
Sally manages to cause Danny to cut himself with a straight razor, regaining her normal appearance and realizing that the vengeful ghost she met earlier was right in how she was to act.
However, Danny comes to the house and confronts Sally, revealing that the exorcist Ilana had told him that there was another way to get rid of a ghost: by destroying the place it haunts.
He begins to set fire to the house, but Sally manages to trap him in with her long enough for Aidan and Josh to return, both revealing their supernatural abilities to Danny.
After reuniting with her friend Stevie at her high school reunion, she confronts the recently deceased former prom queen, making her find her own Door.
At the hospital, after a janitor cleans up a line of salt Zoe uses to keep ghosts out of the nursery, Sally tries to take things into her own hands, but the dark entity attacks her.
When her mother passes, they reunite but at her mom's funeral, Sally sees her kissing the ghost of their neighbor, who died a decade earlier, and realizes the two had been having an affair.
With Sally out cold, the boys approach Zoe for help, but the Reaper takes over, trapping everyone in the house while Aidan is going through blood withdrawals and it is also the night of the full moon.
Later, as Aidan is being buried and Josh is in his standoff with Ray and Nora, Sally's voice comes on over a radio in the house, revealing she has made it into Limbo but she needs her friends' help to get out.
After Josh shows his kinder side to Nora, she begins to reciprocate his feelings, and when she confronts him about his flightiness in their relationship on the verge of a full moon, they have sex.
After this discovery as well as Sally's resolution of her issues, he decides to return to medical school and become a doctor to support Nora and his child, but this celebration is cut short by Bishop's attack on Aidan.
Near the next full moon, Josh is approached at work by a young woman named Brynn who reveals that her twin brother Connor has been put in the psych ward, and that they are both werewolves.
That night is the full moon, so they work fast to try to free Josh, who can only think of the blood still lingering in the house, and the fear he may kill Zoe.
They spend the next 15 months trying to find both Aidan and Sally, and Josh has advanced his medical degree and works at Suffolk County Hospital in a residency.
Originally an Englishman who became a vampire during the 17th century, Bishop travels with his sire Carlo to the Thirteen Colonies and eventually turns Aidan, his wife Susanne, and Marcus during the American Revolution.
In response, having assisted in the death of Bernie's bullies to trick Aidan into killing the boy, Marcus goes to the Amish Country to reveal Bishop's plans to the Dutch.
With the arrival of the Dutch in Boston, Bishop has Josh kidnapped to entertain them in a werewolf death match, releasing him after Aidan agrees to return to his side.
However, during a feast the next day before he revealed that he knew Marcus told them of his plans, Bishop poisoned the Dutch with juniper, laced into the blood of feeding-den prostitutes.
After being convinced by Ray to try having sex just before his monthly transformation, Josh awkwardly comes on to Nora and she rebuffs him by threatening sexual harassment charges against him if he ever speaks to her again.
Now able to see Sally, Nora consoles her after her encounter with Stevie and Dylan, revealing to the audience that she knows she killed Heggeman even though she told Josh she could remember nothing of the transformation.
Killing the woman in front of a room of human onlookers, all of whom were slaughtered under Mother's order to ensure their kind's existence is not exposed, Suren is punished for jeopardizing all vampires by being placed underground for eighty years.
After Bishop's death, Mother decides to release Suren early to take over the Boston vampire instead of Aidan and is stationed in the hotel where she ironically caused the bloody massacre.
Regardless of her dissatisfaction with Aidan, she throws the Dutch out the trail when Heggeman ends up missing as a result of his death at newly transformed Nora's claws.