“An Evil Within” is episode two of season four of Warehouse 13.
In the previous episode, “A New Hope”, the destruction of the Warehouse by Sykes’ bomb was reversed, due to the use of an artefact that affects time, and Artie is the only one who knows it has happened. Before he used the artefact, Ferdinand Magellan’s astrolabe, he was warned that doing so would create an evil of his own making that would live with him for the rest of his days. Claudia has left, presumably to try and use the metronome that was keeping Marcus alive to bring Jinks, who was killed in “Emily Lake”, back to life. Artie also had a vision of Claudia killing him.
This episode opens in Philadelphia. Two men enter a diner talking about something that sounds scientific (actually, whether Vulcans are stronger than Klingons). Another man leaves the place and chains the door shut. Everyone in the place sees a monster appear, and they run towards the rear exit – the one that has been chained shut. A clear health & safety violation. Everyone attacks the monster, but it turns out to be one of the other customers, one the two who entered know. They were seeing something.
Artie is in Claudia’s room at Leena’s, looking at her things. Myka and Pete want to help Claudia, but Artie says that they are not going to help Claudia, he is. They are going to Philadelphia. The person attacked survived, but only just. After Pete and Myka leave, the head of the Templar sect, Father Adrian, the one who told Artie not to use the astrolabe, arrives, looking for Artie. Of course, although Artie has met the Father, the reverse is no longer true.
Father Adrian represents the Vatican, and they want the Warehouse’s help. The Vatican know about the Warehouse. Father Adrian wants Artie’s help recovering an artefact stolen from his care – Magellan’s astrolabe. Of course, Artie was the one who stole it. Kind of. Father Adrian says that the artefact is very dangerous, and that the thief used it to erase 24 hours, and now that needs undoing. As using the astrolabe releases a powerful evil, and the only way of undoing the act is by undoing what happened. Unfortunately, the world in which the astrolabe was used was falling apart. Neither alternative seems particularly good. Artie promises to help find the thief. Which would be very easy after all. He probably isn’t going to tell Father Adrian that.
In Philadelphia, Pete and Myka close down the diner, thinking that they have eliminated the danger as a result. Then some people at a dental office see a monster of their own – which isn’t a monster, but a patient – and the nurse pushes it out a window. A pretty high window. The second man is not as lucky, and dies. The man from the first incident was there as well. Each monster has tentacles. Myka has a phobia for tentacles. The artefact is being deliberately used by the man seen before. The question is why?
Claudia is desperate to bring Jinks back. Using artefacts like this isn’t allowed, as Artie tells her when he finds her. Claudia asks him if he could use an artefact to reverse a huge tragedy, wouldn’t he do so. Which, of course he has – just no-one knows it. However, according to the Regents, Claudia is allowed to bring back Jinks. Artie is concerned that using the artefact to bring Jinks back from the dead will release the evil. Perhaps he’s seen or read Pet Sematary.