Headliner Stan Lee is ill and "physically unable to travel" to this weekend's Amazing Arizona  Comic Convention in Phoenix, organizers announced overnight.

The 90-year-old Lee abruptly canceled two public appearances in September only to reveal he was recuperating after having a pacemaker implanted. “Now hear this!" he wrote in a message to fans. "Your leader hath not deserted thee!" True to his word, Lee was soon as ubiquitous as ever, and recently recorded a reading of "'Twas the Night Before Christmas" as well as a message to a 16-year-old Spider-Man fan critically wounded in a school shooting.

On the convention website, organizers explain refund procedures for attendees who purchased Stan Lee Photo Ops or Stan Lee Packages. The event, which kicks off Friday at the Phoenix Convention Center, features special guest Jim Lee and a creator lineup that includes Scott Lobdell, Joshua Hale Fialkov, John Layman, Cory Walker, Ale Garza, Jason Pearson and Kyle Higgins.