S2E21 · The Calusari

In Murray, Virginia, Maggie (Helene Clarkson) and Steve Holvey (Ric Reid) visit an amusement park with their children. During the outing, Teddy, the youngest child, loses his balloon. His father, Steve, substitutes it with Charlie's balloon. In a tragic turn of events, Teddy follows the balloon onto the tracks and is fatally struck by a train. Strangely, Charlie appears unaffected by Teddy's death.

Three months later, Fox Mulder (David Duchovny) shows Dana Scully (Gillian Anderson) a photo taken moments before Teddy's death that suggests a mysterious force lured Teddy onto the tracks. The agents later visit the Holveys, and Scully grows suspicious of Maggie's elderly Romanian mother, Golda (Lilyan Chauvin), who is seen drawing a swastika on the boy's hand. Scully hypothesizes that the Holvey children may be victims of Munchausen by proxy, perpetrated by their grandmother. As they delve deeper into the case, Steve recalls odd occurrences surrounding Golda's arrival after Teddy's birth. Concerned for Charlie's safety, Scully suggests involving the social worker named Karen Kosseff (Christine Willes). However, tragedy strikes when Steve is accidentally killed in his garage, and when the police investigate his death, they discover evidence of ritualistic sacrifices in Golda's room.

In her room, Golda initiates a ritual with several Căluşari mystics. In the meantime, Kosseff shows up at the Holveys' house and asks to meet with Charlie. Suddenly the boy begins to convulse. After noticing smoke billowing out from under Golda's door, Kosseff and Maggie interrupt the ritual. This, however, leads to Golda's demise at Charlie's hands. Kosseff rushes off and finds Mulder, who in turn questions the Căluşari mystics. They explain that their ritual was an attempt to stop "an ancient and unrelenting evil". Kosseff later sits Charlie down and inquires about the struggle, but the boy swears that it was not him in his grandmother's room, but rather another boy named "Michael".

Maggie later tells Mulder and Scully that Michael was the name of Charlie's twin brother who was a stillborn. Terrified, she insists that she and Steve never told Charlie. After Charlie was born, Golda tried to perform a ritual that would have separated the spirits of the two boys. However, Steve would not allow it.

Charlie seizes again and is taken to a hospital. However, Michael pretends to be Charlie and convinces Maggie to take him home. Scully witnesses what is happening, and informs Mulder, who is certain that the spirit of Michael, and not Charlie, is killing people. The two agents split up: Mulder tracks down the Căluşari mystics to complete the ritual, and Scully goes to Maggie's home to protect her. Although Michael very nearly kills Scully and Maggie, Mulder and the Căluşari manage to complete the ritual, which causes Michael's spirit to disappear. Maggie then returns to the hospital and is reunited with Charlie.