Ep 18. Midnight

In the eighteenth episode of the first season of Fringe, titled "Midnight," the team discovers a group of people with an extraordinary ability known as "mindwalking." These individuals are able to enter other peoples' dreams and interact with them, either for good or for evil. However, when one of these "mindwalkers" goes rogue and starts using their power to commit murder, the Fringe team is called in to investigate.

As they delve deeper into the case, they begin to uncover a sinister plot involving a pharmaceutical company and their experimental drug trials. The drug in question is designed to enhance cognitive abilities, but it also has a side effect - it allows patients to enter other peoples' minds and manipulate their dreams. The company has been using this technology to test the drug on unwitting subjects, and the rogue "mindwalker" is one of their earlier test cases.

To track down the killer, the Fringe team enlists the help of a woman named Grace, who has the ability to enter dreams at will. Together, they enter the killer's mind and attempt to unravel the twisted web of their subconscious. What they find is more horrifying than they could have ever imagined.

Meanwhile, Walter is struggling with his own personal demons. He has been taking an experimental drug to help him remember details from his past, but the side effects are beginning to take a toll on his mental health. As the investigation heats up, Walter's grip on reality begins to slip, and it becomes clear that he may be the key to unlocking the mystery of the drug.

In the final moments of the episode, the team confronts the killer in a surreal dreamscape, and the truth behind their motives is revealed. The killer's actions were driven by a dark, repressed memory from their childhood, and the drugs they were given brought that memory to the surface, driving them to commit heinous acts.

As the sun rises on a new day, the Fringe team is left to pick up the pieces of the shattered lives left in the wake of the killer's rampage. The episode ends on a somber note, as the team struggles to come to terms with the knowledge that our minds can be our greatest ally - or our most dangerous foe.