Paul Sobriki was an ER patient and a law student who originally presented to the ER with headaches, causing Lucy Knight to believe that Sobriki had schizophrenia and although Carter ignored it, they did the necessary bloodwork. At some point, Sobriki suffered a psychotic break and attacked Lucy before lying in wait for Carter whom he then stabbed before Sobriki fled the ER. Dr. Kerry Weaver discovered the two injured Doctors in the room, prompting the Valentine Day party to abruptly end as the ER team worked to save Carter and Lucy.