I Will Follow You into the Dark
| Episode Number | 17 |
|---|---|
| Season | 5 |
| Aired | 2009-03-12 |
| Overview | Derek decides to quit after learning that more of his patients have died than survived; Izzie's interns make an unsettling discovery about "Patient X." |
| Runtime | 43 minutes |
| Absolute Number | 95 |
| Finale Type |