Tear Jerker / Numberjacks

• In "Counting Down To Christmas", Five and Six go to help Agent 20 sort out her problems, it hurts your heart when Agent 20 fails to recognise Six during the events of "Seaside Adventure" when she's been blobbed. Luckily, "Counting Down To Christmas" takes place after the events of "Seaside Adventure", But there's this line in the latter which seems to stab you:
  Six: [Agent 20] should have known me very well, and she didn't know me at all.
• Three's usually the boldest member of the core group, acting like a bigger Numberjack than she lets on. Then you get moments like in "In, Out, Shake It All About" where Three realises just how small she really is.
  Five: We're not scared of you, puzzle bubble.
  Three: (nervous) Aren't we?
• In "The Dreaded Lurgi", Four, Six, and later Three, get an illness that apparently makes them feel "horrible all over". Particularly sad when Six can't even jump high and how Three acts when she catches it. However, there is a light side: unlike most Sick Episode's of kids' programs we actually see them get better.
  Three: (sickly expression) "I'm feeling a bit giddy... (shocked expression) Or maybe it's not that!"