What better way to celebrate the premiere of Boardwalk Empire, the new HBO series that takes place in Atlantic City, N.J., at the onset of Prohibition, than to enjoy a free drink at a speakeasy?

HBO teamed up with ad agency PHD USA and SET Japan on a promotional initiative for which a QR code designed by SET Japan appeared on ads for Boardwalk Empire on bus shelters in New York and Chicago. Smart-phone users who scan the QR code will receive passwords granting them entry to invite-only speakeasy events, the locations of the events, and one free drink.

In New York, the QR code-enabled ads can be found on 42nd Street between Third and Lexington avenues; on 86th Street between Columbus and Amsterdam avenues; and on 79th Street between Third and Lexington avenues.