user: Question: Who is the directed by when the production code is 67425?
Columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'real']
Sample row: [23.0, 1.0, '"Confession"', 'Fred Gerber', 'Michael Duggan & Robert Palm', 'September 17, 1991', 67416.0]
SQL:

assistant: SELECT "Directed by" FROM "Table" WHERE "Production code" = 67425.0;