Patrick Stewart will make his welcome return to the "X-Men" series in the upcoming "Days of Future Past," but as he explained to MTV News when he stopped by our offices, the resurrection of Professor Charles Xavier was something he had heard rumors about beforehand.

"There had been murmurs. In fact, with something like that, it's impossible to keep the murmurs down," Stewart said. "I just hoped the call would come. Ian and I got on the phone and said, 'Have you heard?' "

And it shouldn't have come as too big of a surprise once the call did come because of the special ending hidden after the credits of "X-Men: The Last Stand," which revealed that Prof X inhabited the body of a formerly comatose hospital patient.

"They had left the window open for Magneto and Xavier to come back, that is if you stayed until the end of the credits of ['X-Men 3']," Stewart said. "You'd be amazed at how many people didn't. They go, 'There was what?' "

And even though Xavier is back in the fold, who knows how long he'll stay around? Stewart said that he didn't see why Professor X wouldn't be back for the next film, "X-Men: Apocalypse." His comments about death in the genre, however, have us scratching our heads.

"That is one of the blessings about fantasy and science fiction. You're never really dead. I would love to come back and do some more," he said. "There might be something else. A little bird has whispered that there might be something 'X-Men' related."

Is that a possible hint of what's to come in "Days of Future Past"? Tell us what you think below.

"X-Men: Days of Future Past" opens in theaters on May 23.