user: Question: Who was the away team that played Northampton Town at home with a tie number of replay?
Columns: ['Tie no', 'Home team', 'Score', 'Away team', 'Attendance']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['21', 'Morecambe', '2 – 1', 'Grimsby Town', '1,713']
SQL:

assistant: SELECT "Away team" FROM "Table" WHERE "Tie no" = 'replay' AND "Home team" = 'Northampton Town';