Fantastic Four, Vol. 3 #544A

The Initiative - Reconstruction, Chapter One: From The Ridiculous To The Sublime* (*But Not Necessarily In That Order)
Black Panther and Storm announce their temporary visit to the Baxter Building, and their homes with the Fantastic Four. Their first mission: find out what happened to Gravity's body, stolen after he gave his life in an encounter with the Stranger (as depicted in the "Beyond!" miniseries.)
Release Date: 2007