FAIRY TAIL Vol 39

From the Kodansha edition

The fateful day is finally here: July 7, X791! A lunar eclipse presages an invasion by ten thousand dragons. Humanity's only hope is the Eclipse Cannon, but what waits behind the door: hope or despair? Will history repeat itself, and Earthland be taken over by dragons once again? The time has come for the dragon slayers to prove their magic lives up to its name!

Source: Anime News Network Encyclopedia