SELECT COUNT("Episode Number") FROM table_21434 WHERE "Event 4" = 'The Wall' AND "Event 1" = 'Pendulum'
On which episode number is event 4 The Wall and event 1 the Pendulum?
CREATE TABLE table_21434 (
    "Episode Number" real,
    "Air Date" text,
    "Event 1" text,
    "Event 2" text,
    "Event 3" text,
    "Event 4" text
)