Without A Trace (2002) - 5x07 - All the Sinners, Saints

Martin and the team search for Katie, a young woman who goes missing after a priest performs an exorcism on her.

Katie's brother asks for Martin's assistance because Katie spoke fondly of him when she interned at the FBI when Martin was still working on White-Collar crimes. He and the team soon discover that the priest, who also vanished, was suspected of murder last year when a man died during his exorcism. They also learn that Katie scheduled the exorcism because her mental illness, well managed with medications for many years, is now causing her to feel like she's being possessed by something "dark." Meanwhile, Jack and Anne forge ahead with their plans to buy an apartment together as they prepare for their baby's birth.