Melissa Scully: I don't have to be psychic to see that you're in a very dark place. Much darker than where my sister is.
Willingly walking deeper into darkness cannot help her at all. Only the light...
Mulder: [disgustedly] Oh, enough! - with the harmonic convergence crap, okay, you're not saying anything to me.
Melissa Scully: [angrily] Why don't you just drop your cynicism and your paranoia and your defeat. You know, just because it's positive and good, doesn't mean it's silly or trite. Why is it so much easier for you to run around trying to get even than just expressing to her how you feel? I expect more from you. Dana expects more. Even if it doesn’t bring her back, at least she’ll know. And so will you.
Shadow Archetype: X says he used to be Mulder, but that he had the heart to do the things that Mulder can't and won't do.
Shell-Shocked Veteran: Skinner talks about how he lost his faith in everything after shooting a child covered with grenades in Vietnam. He also reflects on a later near-death experience and how he's afraid to look beyond it.
"You got him killed! You got her killed. That's not going to happen to me. You're my tool, you understand?! I come to you when I need you!"
Later, Melissa Scully calls Mulder out pretty spectacularly when he refuses to come to the hospital for what could be Scully's last night.
Melissa: Why don’t you just drop your cynicism and your paranoia and your defeat. You know, just because it’s positive and good doesn’t make it silly or trite! Why is it so much easier for you to run around trying to get even than just expressing to her how you feel? I expect more from you. Dana expects more. Even if it doesn’t bring her back, at least she’ll know. And so will you.
Unusual Euphemism: X tells Mulder that he later needs to be prepared to "defend [himself] with terminal intensity".
Villain Respect: CSM admits he actually likes Mulder and Scully. He also believes Mulder is becoming "a player" in the overall game.
Why Did It Have to Be Snakes?: Subverted with Agent Scully. Her mother tells a story how her daughter felt guilty for shooting a snake with her new BB gun. Although deathly afraid of snakes, she held the snake and it died in her hands. When Mulder and Scully investigate cases involving snakes, she isn't exactly on edge ("Die Hand die Verletzt") and she even gets a tattoo of a snake eating its own tail in "Never Again". On the other hand, there are lots of snakes in "Signs and Wonders", but even Mulder who doesn't suffer from this phobia is very nervous around them.