"Subland Empire"
*Run the mission! Don't get seen! Save the world! A secret city buried one mile under American soil is discovered through the leakage of Von Doom radiation – a type of energy emitted only by time-travel devices. So the Secret Avengers head underground to a weird metropolis forgotten about for decades, because a time machine in the wrong hands is the worst kind of WMD imaginable. Master storyteller Warren Ellis begins his tenure on Earth's Mightiest Clandestine Super-Team, illustrated by Eagle Award-winning Jamie McKelvie. *Source: marvel.com