Secret world chronicles

When world governments are simultaneously attacked by soldiers in giant mecha robotic suits with the swastika symbol of the Third Reich on their metal arms, the metahuman superheroes that worked for so long to protect their governments suddenly seem helpless. If these were Nazis, where had they been hiding since the end of World War II? And where had they gotten armor and weapons far in advance of anything on the planet?

"From New York Times best-seller and science fiction and fantasy mistress of adventure Mercedes Lackey, Book #3 in a new pulse-pounding saga of modern-day humans with superpowers. The metaheroes deal with supervillain Verdegris, who seeks to destroy them from within, before turning their attention back to the Thulian conspiracy. It's go time once again for the meta-heroes including fire-bender John Murdock, hacker-witch Vikki Nagy, healer Belladona...

"Ultima Thule has been destroyed but not before destroying Metis. The Metisians that escaped the destruction of their secret city must find somewhere safe without getting snapped up by various world governments. Now attacks are happening all over the Earth. The heroes of ECHO and CCCP have to save the world but first, they have to save each other. And the avalanche has begun"--