Unable to find an antidote for the poison that a Skrull had slipped Beast's ex-girlfriend, Vera Cantor (Avengers #209), Mr. Fantastic suggested that they seek the help of Dr. Strange (Defenders #105).
The master of the mystic arts took the lead as the trio ventured into the extra-dimensional realm tied to the Resurrection Stone. They did not realize it at the time, but the malevolent spirit of the gemstone had mentally lured the three heroes to that dimension to harness their life force. The battle ended as the entity transformed Dr. Strange, Mr. Fantastic, and Beast into crystalline statues, frozen within the magical realm.
They weren't the only ones trapped in another dimension.
After their epic mission to hell (Defenders #99), one of the Defenders had not returned to Earth (#101). Daimon Hellstrom, the Son of Satan, remained a prisoner in his father's domain.
As he tortured his son, the Lord of Lies added insult to injury by flatly describing the interdependence between good and evil, and the conflicted nature of evil itself (#105).
- Satan: Still, I have my role to play--you have yours! We are sworn enemies--we must fight each other through eternity! But know that, behind the facades--your father loves you! I do not expect you to fully comprehend this, Daimon. Few could without going mad. That is why this memory will fade from your mind … leaving behind only a glimmer of what you've learned. Now--return to your human friends, whelp! The sight of you sickens me!
Cast out of hell, the Son of Satan materialized in the home of Dr. Strange, where the Resurrection Stone had restored itself. Using his own magic, Hellstrom instinctively destroyed the gemstone once and for all—thereby freeing Beast, Mr. Fantastic, and Dr. Strange. Hellstrom then used his healing powers to return Vera Cantor to health.