Warren Ellis pens six standalone tales that plunge the Secret Avengers into a world of underground black-ops insanity they could never have imagined! A forgotten underground metropolis, Yugoslavian bio-terror, a world-threatening bomb from a broken universe, an ancient and terrible threat mined by drug lords, a time-travel adventure to save the team, and a dangerous investigation into the offices of?O*N*E – can the Secret Avengers triumph over the hidden horrors of the world? Collecting SECRET AVENGERS #16-21.