Complex sentence: At Cordy's apartment, Fred and Gunn stumble upon Dennis's birthday celebration for Cordelia then search the apartment for signs of Cordelia's health struggle or any other potential cause for her comatose state.
Split into simpler sentences: At Cordy's apartment, Fred and Gunn find Dennis's springing his own surprise birthday celebration for Cordelia. They search the apartment for signs of Cordelia's health struggle or any other potential cause for her comatose state.