Gregor and the curse of the warmbloods.

In this book Gregor once again goes to underland. Accept this time Gregor's mom comes with him. There is a disease spreading in the underland called the plague. Ares, Howard, Andromeda, and Gregor's mom are the four cases of plague in Regalia.Gregor has to go on a quest to where the plague had started and find a flower that is predicted to cure the plague. Will Ares, Howard, Andromeda, and Gregor's mom die before Gregor, Solovet, and Ripred find the flower? Read to find out!