Valerian Graphic Novel Volume 21 Time Opener

"The conclusion of Valerian and Laureline's adventures, the end of a 40 years saga! The evil hordes of the Wolochs are rampaging through space, and everywhere death and destruction follow. But despite the despair of some and the betrayal of others, Valerian, Laureline, and a few other brave souls are resisting. They're hoping to use a mysterious artifact, the Time Opener, to banish the stones and bring back Earth. But what price must they pay to do so? And what sort of Earth will they get back if they succeed?"