X-MEN #21

"EXOGENOUS" Part 4 of 5! •  As the X-Men race to find the origins of the threat that has emerged from deep space, they discover that there's a larger conspiracy at work...one that may have its roots close to home! •  What are Agent Brand's ties to the mysterious Providian order? •  How could Deathbird's secret upset the balance of the cosmos? •  And what does the third Summers brother-and Rachel Grey's uncle-Vulcan have to do with it all? Rated T+