user: Question: How many have Mrs. Briar as a villain
Columns: ['No.', '#', 'Title', 'Director', 'Writer', 'US air date', 'Storyteller', 'Villains']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [40.0, 1.0, '"The Tale of the Renegade Virus"', 'Ron Oliver', 'Andrew Mitchell & Gerard Lewis', 'October 1, 1994', 'Gary', 'The Virus']
SQL:

assistant: SELECT COUNT("No.") FROM "Table" WHERE "Villains" = 'Mrs. Briar';