- The deaths. Dear lord, where do we begin?
- Booth accidentally shooting himself and then bleeding to death, despite Malcolm's attempts to help.
- Thomas being killed, just after he and Trish mend things between them.
- Charlie trading his life for Jimmy's, as well as his final conversation with Abby.
- Shane's Heroic Sacrifice, which doubled as a Redemption Equals Death moment.
- Cal and Chloe's Together in Death.
- Danny giving his life to save Madison and Shea from Wakefield; he fights as hard as he can, but in the end, it's not enough and Wakefield takes him out.
- Trish being killed by the man she loves while in her wedding dress.
- Sully's reaction when Henry (his best friend since junior high) reveals himself to be Wakefield's son and accomplice, and then Henry stabs him in the back literally. Made all the more heartbreaking when, shortly beforehand, Sully refused to escape the island when he had the chance because he didn't want to leave Henry behind.
- The fact that Danny, Trish and Sully were all wasted mere hours before the Coast Guard could rescue them, the latter two by someone they loved and trusted who was lying to them the whole time until he showed his true colors at the eleventh hour. They were so close!
- Henry's death.
- Abby and Charlie's estranged relationship.
- Shea finding out that Richard has been cheating on her with her stepmother, Katherine.
Tearjerker / Harper's Island