Odd Squad (2014)

S1E15 The Odd Antidote / The One That Got Away

After Ms. O experiences strange reactions from being sprayed with a peculiar plant, Olive and Otto embark on a quest around the town to gather the precise ingredients needed for her antidote, all while concealing her illness from her. The only thing that can coax Ms. O’s former partner, O’Donahue, back into action is the same enigma that forced him into retirement: a shadowy adversary and a long-standing mystery that remains unsolved.