|"Immune to All but Justice"|
|Airdate:||October 18, 2003|
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"South of Friendship, North of Honor"
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"The Shreds Fell Like Snowflakes"
Immune to All but Justice was the twenty-first episode of Fillmore! to be produced and the eighteenth to air. It was originally broadcast on October 18, 2003.
Ingrid and Fillmore are dealt with a though case. They know who the culprit is. However they cannot arrest him as he has Diplomatic Immunity, meaning he cannot be charged for any crime. Fillmore and Ingrid need to decide whether to leave Winston Kotter alone and follow the book or taking him down which would lead them to being thrown out of the safety patrol.
During a diplomatic mission by Canadian ambassor Winston Kotter, Fillmore is reunited with Penny Madrid, his ex-girlfriend. However, their reunion is cut short when Fillmore and Ingrid expose Winston's illegal counterfeit operation and bust him. However, it is revealed that Winston has diplomatic immunity, and Principal Folsom lets him go. Vallejo warns Fillmore and Ingrid against investigating further.
Fillmore and Penny reminisce about their days as juvenile delinquents, when they bullied kids for lunch money. When asked by Fillmore about Winston, Penny reveals that working for him turned her around.
Later, when Fillmore and Ingrid uncover a stack of missing counterfeit baseball cards, Vallejo suggests going through some proper channels, which prove to be ineffective and inefficient. Penny tips them off to a hideout at the loading bay. Sure enough, they encounter Winston and several thugs, whom they lose in an ensuing chase.
They go to Canada, and Fillmore confronts Winston, who lodges a complaint against him and Ingrid, earning the two a stern warning from Vallejo. Fillmore and Ingrid elect to continue their investigation in secret, and reluctantly accept Penny's help.
While tipping them off about Winston's base of operations, Penny is found out by Winston, who plan to have her expelled for the operation. When confronted by Vallejo, Fillmore and Ingrid surrender their badges and sashes and leave to rescue Penny.
After rescuing Penny though, they receive unexpected help from Vallejo and the Safety Patrol, who stop Winston and his goons in his tracks. Winston is given a stern warning by Vallejo and is forced to return to Canada in disgrace.
However, the counterfeit baseball cards are still missing. At her house, Penny accidentally reveals to Fillmore that she knows about the missing cards, and finally confesses to have assisted Winston in the operation with the intention of seizing control. Fillmore subsequently breaks up with her for good and has her arrested.