SPOILERS: We’ll be talking about what happens in House of X #3 and the important back issues to help you understand the back story to this tale

House of X #3 brings us back to the current day in a more familiar setting of the X-Men going on a mission. We are getting even deeper into Sentinel lore, so here are a few more back issues to consider reading up on before or after reading of House of X #3.

Sentinels and the Sun

Though there is no direct link to this story, it does parralel nicely as the X-Men fly into space approaching the sun to destroy a Sentinel. In Uncanny X-Men #59, cyclops destroys a sentinel by convincing it that th Sun is responsible for mutants due to its radiation, therefore choosing to attack the sun.

Operation Zero Tolerance an Omega Sentinel

Bastion, the merged and reworked Nimrod and Master Mold, unleashes his plan which involve capturing the world’s mutants, including our X-Men. We meet the latest version of the Sentinel, the Prime Sentinel, which are basically humans with advanced prosthetics who are sleeper agents that become activated as Sentinels. Operation Zero Tolerance was told across a number of issues, though the main collections focus on Generation X #27, X-Force #67-69, X-Men #65-70, Wolverine #115-118, Cable #45-47 and X-Man #30.

Karima Shapandar is an Omega Sentinel created during Operation Zero Tolerance. She was first introduced alongside the new Thunderbird Neal Shaara in X-Men Unlimited #27. She encounters Xavier and Magneto as they inhabit a devasted Genosha. Her programming is disabled and she joins the duo on Genosha in Excalibur (3rd series) #4. She joins the X-Men and remains somewhat active until she is rendered completely human in X-Men #3. Karima has returned as Omega Sentinel in House of X #1, and is featured more prominently as an adversary in House of X #3.

Sol’s Hammer

Sol’s Hammer is one of the few concepts we’ve seen from previous Hickman-penned comics that has come up in this run. It is a dyson sphere constructed by Iron Man as a contingency of colliding planets. It was first revealed in New Avengers (2013) #4 and apparently destroyed in Avengers (2013) #44. It returns in House of X #3 as the basis for the Mother Mold.