The Ultimates, Vol. 2 #4 (2005)

Brothers
The Ultimates are called to Europe after Thor kills several Italian police officers. A Norse scientist informs them that Thor is not actually a god, but is rather a lunatic with a big hammer, wearing a harness designed to make him the most powerful superhuman on the planet. The Ultimates are dispatched, along with Captains Britain, France, Spain and Italy to bring Thor in or put him down.
Release Date: 2005