On which episode number is event 4 The Wall and event 1 the Pendulum?
CREATE TABLE "episode_events" (
  "episode_number" real,
  "air_date" text,
  "event_1" text,
  "event_2" text,
  "event_3" text,
  "event_4" text
);
SELECT COUNT("episode_number") FROM "episode_events" WHERE "event_4"='The Wall' AND "event_1"='Pendulum';