|"Baby Kate and the Imaginary Mystery"|
|Number in season:||5a|
|Original Airdate:|| June 29, 2007|
December 31, 2007
December 13, 2007
|Written by:||Peter K. Hirsch|
|Storyboard by:|| Elie Klimos|
"Brain's Shocking Secret"
"Strangers on a Train"
Pal and Kate fear Nadine has been kidnapped by the Tibbles, so they set out to investigate.
- Timmy and Tommy Tibble
- David Read
- Arthur Read
- D.W. Read
- Mrs. Tibble
- Uncle Wormy
- The Xfinity description guide calls D.W. a boy while saying, "D.W's imaginary friend Nadine is missing, so his real-life pals set out to find her".
- In the beginning of the episode, Pal breaks the fourth wall by telling Kate that the viewers don't say anything even when Arthur talks to them.
- The Om_ble backpack from "D.W.'s Backpack Mishap" is seen in this episode.
- Mashed Peas Theater is also seen in "Invasion of the Soccer Fans".