: George O'Malley faces an emotional crisis when almost all the students from the accident die under his care, leaving him devastated until Owen Hunt helps him see the lives he did save.
While the wedding takes center stage, the hospital remains in chaos due to a tragic car crash involving college students on their way to graduation. [S5E22] What a Difference a Day Makes
: Creator Shonda Rhimes noted that Denny's appearance in this episode was meant to represent "Death," which is why he wore black and spoke sparingly compared to previous appearances. : George O'Malley faces an emotional crisis when
: As a wedding gift, Derek gives Meredith her first solo surgery—a successful colon surgery overseen by Richard Webber. : As a wedding gift, Derek gives Meredith
The episode's central plot twist occurs when Meredith and Derek decide to give their meticulously planned wedding to Izzie and Alex.
: Rhimes described the episode as the moment Meredith evolved from a "dark and twisty" girl into an "extraordinary" woman capable of choosing happiness.