Question: What is the episode number for "Case Two (Part 1)"?
SQL: SELECT "Episode" FROM "1-21369888-4" WHERE "Title" = '"Case Two (Part 1)"';

Question: What is the original air date for the episode viewed by 7.12 million?
SQL: SELECT "Originalairdate" FROM "1-21369888-4" WHERE "Viewing Figures (millions) Sourced by BARB ; includes ITV1 HD and ITV1 +1" = '7.12';

Question: Who directed the episode viewed by 7.35 million?
SQL: SELECT "Directed by" FROM "1-21369888-4" WHERE "Viewing Figures (millions) Sourced by BARB ; includes ITV1 HD and ITV1 +1" = '7.35';