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_19930660_2 (marcus_guest VARCHAR, rufus_guest VARCHAR)

### Question ###
Who was Marcus's guest in the episode when Rufus's guest was Rory McGrath?

### Accurate SQL ###

SELECT marcus_guest FROM table_19930660_2 WHERE rufus_guest = "Rory McGrath"