Incredible Hulk #169

"Calamity in the Clouds!" - The Harpy has just defeated the Hulk, and as General Ross watches the news coverage on TV he rushes out to the scene of the battle, recognizing the Harpy as his daughter Betty. When he confronts his daughter he tries to talk her out of killing the Hulk. Thinking it's all a trick she flies away with the Hulk in her clutches. When the military sends out fighter jets to stop her she shoots one out of the sky before she and the Hulk are swept up in a strange tornado that sweeps them into a giant cloud mass.  They soon find themselves in some strange city hidden in the clouds. As the Hulk revives they are confronted by a two-headed creature calling itself the Bi-Beast.