Season 4

While Kenzi, Hale, and Dyson, are all living their lives, Bo is nowhere to be found. It's later realized that they simply forgot Bo, as someone was forcing them to. Massimo has been giving Kenzi temporary powers to appear Fae. Bo finally awakens to find herself on a train, and later jumps off. A group of Fae called the "Una Mens" are introduced. When she arrives home, it is discovered that while Bo herself did not consciously choose a side, her blood has chosen Dark. Tamsin is found reborn, as a little girl, and grows up with Kenzi as her pseudo-mom. Massimo steals from Bo and Kenzi in an attempt to convince Kenzi to pay him, and Bo figures out that he is not Fae, but human. He also kidnaps Tamsin to acquire her Valkyrie hair, and after being defeated by Bo, chases after the hair into a pit of lava, where at that point he is assumed to be dead. Many of Trick's secrets and past actions are revealed, including a tie to a past life of Tamsin's, and the fact that he used his blood to "erase" someone from existence. Tamsin discovers that by not taking the soul of a man named Rainer to Valhalla, she is part of the reason "The Wanderer" was created. Bo is able to get back on the train, where she finally meets Rainer, and brings him back to the Dal. Hale and Kenzi admit their feelings for each other. Lauren, who has been working with the Dark, somehow turns the Morrigan human. Kenzi's mother is introduced, and Hale attempts to propose. Massimo returns, and protecting Kenzi, Hale is killed. Kenzi tries to get revenge, but is stopped by Vex, who mentions that he is Massimo's guardian. Evony is revealed to be Massimo's mother, and gave him to Vex years ago when he was a boy. Bo learns that not only is her father coming, but that to close the portal, she will need to give her heart. That is revealed to be Kenzi, who sacrifices herself. It ends with Bo visiting Kenzi's grave.