Table schema:
CREATE TABLE table_17467147_1 (series__number VARCHAR, directed_by VARCHAR, written_by VARCHAR)

Question: When debra j. fisher & erica messer are the writers and the director is patrick norris what is the series number?
SQL: SELECT series__number FROM table_17467147_1 WHERE directed_by = "Patrick Norris" AND written_by = "Debra J. Fisher & Erica Messer"