New York City's underground can now be considered the next kingdom in the Game of Thrones.
The popular HBO series, which returns in April, purchased advertising from MTA NYC Transit.
This week, MetroCards that feature Game of Thrones characters appeared in the system.
There are four cards. 250,000 have been printed and they're available at the main turnstile area of Grand Central.
In November, posters for the show appeared at the station. It is the second busiest transit hub in the NYC system.
The agency has been increasing revenue from advertising sales.