This issue takes place right after Hulk #91, in which Hulk was tricked into a mission and then exiled into space. As part of the Illuminati, Reed was one of the folks who manufactured the crisis that was used to lure Hulk. In this issue, he destroys the evidence but makes Sue suspicious.
This is all groundwork for Civil War, where Reed and Sue will find themselves on different sides. It’s well done. This series has suddenly improved to the point where I no longer dread reading it. It’s ALSO related to Planet Hulk, so this issue has the rarified distinction of being part of the two biggest events of this year.