The deal serves to highlight the The Amazing Spider-Man 2 DVD release tie-in with a specially decorated/designed Amazing Spider-Man 2 Crave Case, while supplies last.
A White Castle Crave case comes with 30 of the chain's signature sliders. Prices start at around $20 for 30 Original Sliders and $25 for 30 Cheeseburger Sliders (pre-discount).
The online deal is good through 6 am on September, 22, 2014.