- The conclusion of the fourth episode, when Connor comforts his delirious best friend as he slowly dies from the parasite. And afterward, he stands up and turns to Nick and says that he can't handle being part of the team anymore, and Nick gives him a hug.
- When Abby is (apparently) lost forever to the Mer creatures in 2.4. Seeing Connor so distraught and nearly in tears is especially heartbreaking considering the bad feeling the two of them had been sharing directly prior to it. Worse still, Lester (who is still a Smug Snake at this point in the show) orders him to go home and do nothing.
Connor: *fighting desperately not to cry* "We can just go out there and we can find her! All we need to do is get back in the boats and do something; why is nobody doing anything!?"
"I know how you feel."
- Nick's phone call to Connor. Also counts as a Crowning Moment of Heartwarming.
- Hell, that entire episode was really one big Crowning Moment of Character Development.
- Stephen's Heroic Sacrifice in the season 2 finale.
- And the funeral. Everyone's just so silent.
- Nick tearing up the photo of Claudia, showing he's finally given up on getting her back.
- Jenny finding it again after his death, taped back together. Guess he really couldn't let go after all.
- Shortly thereafter, Cutter's death during season 3, particularly his last words. This soon prompted the real heartbreak of Jenny leaving the Arc, closing the chapter for good on Cutter and Claudia/Jenny.
- What makes it worse is that as he dies, the change in his relationship to Connor is suddenly glaringly obvious. They went from Teeth-Clenched Teamwork, with Cutter firing him in the second episode, to Connor being Cutter's closest friend and confidant, and Cutter dying in his arms.
- Also his last words to Connor; after two and a half seasons of being the Plucky Comic Relief, finally someone believes in Connor, and Cutter's last words are ones of encouragement and pure faith that Connor will make him proud. Gah.
- The characters' reactions to seeing him dead make half the Tear Jerker, particularly Lester shouting angrily for an ambulance, in frantic denial.
- The first few minutes of the following episode managed to be Tear Jerkers without even doing anything at all. Just the whole mood of the characters and the ARC was able to convey how upset and lost everyone was without him.
- In the final scene of the Season 4 premiere, Connor wakes up to find Abby already up. He correctly deduces that she's still used to keeping watch from when they were stuck in the Cretaceous. That fact just hammers home the absolute hell those two went through.
- Becker in Webisode #1 before series 4. It's possibly the most expressive we've ever seen him, and it is heartbreaking. He can barely talk without crying, and his grief-stricken, desperate indecision over whether to rejoin the team is enough to make anyone cry.
- The death of the high school girl at the jaws of the Therocephalian in 4.4 is rather devastating, especially since they play it up to make you think she might make it.
- Jess's reaction, too.