Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_12 (nat VARCHAR, transfer_fee VARCHAR, type VARCHAR)

### Question ###
What is the Nat with a mutual consent loan return and has a free transfer fee?

### Accurate SQL ###

SELECT nat FROM table_name_12 WHERE transfer_fee = "free" AND type = "mutual consent loan return"