user: Question: On which episode number is event 4 The Wall and event 1 the Pendulum?
Columns: ['Episode Number', 'Air Date', 'Event 1', 'Event 2', 'Event 3', 'Event 4']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '30 March 2008', 'Gauntlet', 'Duel', 'Pyramid', 'Pendulum']
SQL:

assistant: SELECT "Episode Number" FROM "Table" WHERE "Event 4" = 'The Wall' AND "Event 1" = 'Pendulum';