Survival of the Fittest

S7 E17: A demented patient causes a shootout in the emergency room. After terrorizing people in the ER with a gun, she gets shot by a policeman. She soon dies. Benton later discover her dementia was caused by an aftereffect of his surgery that he and Cleo should have detected. Carter pursues a cute intern. After a particularly long surgery, Corday decides to take her maternity leave. And April Fool's pranks abound in the ER.