CREATE TABLE table_27987768_1 (no_in_series NUMBER, written_by VARCHAR2)

What number in series was the episode written by Eric Gilliland?
SELECT MAX(no_in_series) FROM table_27987768_1 WHERE written_by = "Eric Gilliland"
SELECT MAX("no_in_series") FROM "table_27987768_1" WHERE "Eric Gilliland" = "written_by"