Another Marvel comic book series appears to be coming to an end: "The Ultimate Universe."

Marvel Comics revealed an "Ultimate Universe" poster last week that read "The End?" Comic book aficionados debate and speculate whether it is indeed finishing, or that it is a tease for something bigger to arrive.

This particular poster featured a plethora of old, new and out-of-print comic book characters. It is surprising to think that Marvel's "Ultimate Universe" is going supernova, but in recent weeks with the "Fantastic Four" going on hiatus, and the upcoming debut of "Squirrel Girl," the end seems possible. In addition, sales for the series have been up and down. 

"The End?" poster, which was created by Mar Bagley, could be referencing something else, Comic Book Resources reported. The concept of "The End" has been mentioned in various Marvel mini-series that ran from 2003 to 2007. The endings were all hypothetical finales of various aspects of the Marvel Universe.

However, the poster does feature a new who's who of the Ultimate Universe such as Miles Morales as the Ultimate Spider-Man and the recently canceled Future Foundation. The poster also has deceased characters Cloak and Dagger, Newsarama reported.

Marvel's Ultimate Universe has been involved in the widely popular "Secret Wars," a Marvel 12 issue "mega event," as well as the "Ultimate Fantastic Four," the "All New X-Men," as well as the upcoming "Spider-Verse."

The end of the "Ultimate Universe" may have already been predicted considering that as of Feb, the only comic book to come out of that particular section is Miles Morales' Ultimate Spider-Man.

What does it all mean? The poster is in the latest series of teaser images put out by Marvel, ComicBook.com reported. The teasers are planned Marvel comic book installments scheduled for the summer 2015.