A little into the surgery, an assistant asks about some unusual bleeding. Jack knocks him out and reveals that he has sliced Ben's kidney sac and will let him bleed to death unless the Others set Kate and Sawyer free.
Full list of appearances
"Under the Knife" and its variations play during the following scenes:
- Jack begins Ben's operation. ("I Do")
- The operation continues. Kate and Sawyer escape their cages. ("Not in Portland")
- In a Previously on Lost recap, Naomi dies. A group of survivors leave with Locke. ("Confirmed Dead")
- Juliet tries operating on young Ben. ("Whatever Happened, Happened")
The title refers to Ben's being under the surgical knife.