Season 6, Episode 24
When the children from neighboring town Shelbyville steal an ancient lemon tree from Springfield, the kids led by Bart, Nelson and Milhouse go to get it back.
Enjoyable episode which has a splendid moment where the gate keeper of the car impound chews into a lemon without considering the consequences.
The title is a reference to: Helen Of Troy.
See here for more details.
Notes & Screenshots: Lord Heath