Codename: Havok
Real Name: Alexander Summers
Height: 6'0"
Weight: 175 lbs.
Group Affiliation: The Six
Previous Affiliations: The Brotherhood of Mutants, X-Factor, X-Men
First Appearance: Uncanny X-Men #58
Known Allies: Lorna Dane, Forge, Ever, Ororo Monrue
Known Relatives: Scott Summers (Cyclops, brother), Christopher Summers (Corsair, father), Katherine Summers (mother, deceased), Philip Summers (grandfather), Deborah Summers (grandmother), Jean Grey-Summers (Phoenix, sister-in-law), Madelyne Pyror (in 616 reality, sister-in-law; in his present reality, wife), Scottie Summers (in present reality, son)
Known Enemies: The Living Monolith, Sauron, Erik the Red, Dark Beast

Powers: Alex has the mutant ability to absorb ambient cosmic energy and release it in the form of high power, plasma blasts. His plasma blast is usually lethal, except in rare times he has had control over his powers. Alex's mutant power cannot affect Cyclops, similar to how Cyclops' power cannot affect Havok. Alex has used various forms of control, the most common being a suit that can monitor his energies (the first was one created by Larry Trask to control Havok). In his current body (in an alternate universe), Havok has nearly complete control over his powers, rather than in his former body, where he had little control at all.

Origin: Alexander Summers is the younger of the two sons of Christopher Summers, a United States Air Force Major and test pilot, and his wife Katherine Anne. Alex and his mother and older brother Scott were flying back from a vacation in Christopher's vintage airplane when the plane crashed into a scout ship of the Shi'ar Empire, setting the wooden plane ablaze. Katherine Anne Summers pushed Scott and Alex out of the burning plane with the only available parachute. Thus the two boys escaped the Shi'ar while their parents did not. Scott and Alex both believed their parents had been killed until as adults they were reunited with their father, who had since become Corsair, leader of the Starjammers, a starfaring band of adventurers. The two boys were hospitalized for injuries they sustained during their landing, since their overburdened parachute had been unable to slow their decent safely enough. Scott and Alex both suffered traumatic amnesia regarding the plane incident. Alex left the hospital after two weeks and was placed in an orphanage in Omaha, Nebraska. Soon adopted, Alex had little or no contact with Scott until years later.

Alex was unaware of Scott's developing mutant power or his identity as Cyclops of the X-Men until after the younger Summers had graduated from college. It was at that time that Alex first became aware of his own mutant abilities. A professor of archeology named Ahmet Abdol, also a mutant, had discovered a psychic link between himself and Summers. While both of them had the latent mutant power to absorb and transform cosmic radiation, Abdol's ability to exercise the power was jammed in an unknown manner by Summers' body. The Living Pharoah, as this mutant was calling himself, captured the youth and took him to his laboratory in Egypt. Abdol found a way to screen Summers' body from ambient cosmic radiation, permitting his own body to attain its latent potential. Abdol was transformed into the Living Monolith, a gigantic mutant with vast cosmic power. The Monolith was defeated while in combat with the X-Men when Summers' latent mutant powers surfaced under the stress of entombment within the mechanism designed to screen him from cosmic radiation.

Incapable of controlling the shock waves his body emanated, Summers chose to remain in the Egyptian desert rather than accompany the X-Men back to America. Summers was soon captured by one of the mutant-hunting robotic Sentinels and brought to the headquarters of Larry Trask, the son of the Sentinels' inventor. Trask gave Summers the codename Havok and a costume whose chest display monitored the build-up of cosmic energy within him. When the X-Men finally freed Trask's captive mutants, Summers accompanied his brother and his teammates back to civilization where he began training to help him keep his energy in check. Eventually Havok gained enough mastery over his power that he would release it only when he wished to do so, and could wield his power skillfully enough to become a formidable opponent in battle.

Havok fell in love with Lorna Dane, the mutant now known as Polaris. They both served for a time in the X-Men helping to repel the invasion by the alien Z'nox. Neither Havok nor Polaris wished to lead a life as an adventurer, but they discovered that they had a mutual interest in geophysics. Hence, they began doing doctoral research in that subject in the Diablo mountain range in Arizona. The plan to stay out of the affairs of the outside world did not last long. Havok and Polaris found themselves hunted by the Marauders. Polaris was now under the mental control of Malice. Polaris was forced to attack the X-Men as the leader of the Marauders. Havok, now a member of the X-Men, had to fight his lover. Polaris was eventually freed from Malice's control, but was captured by the mutant named Zaladane, who claimed to be her sister and stole her powers. For a short while, Polaris gained new superhuman powers.

Later, Polaris regained her original powers and, with Havok, joined the second version of X-Factor, a newly-formed, governmentally-funded, mutant agency. Havok continued to serve with X-Factor until he felt that there were too many people in his life that had been controlling him. He was also deeply affected by the apparent death of his teammate Jamie Madrox. Disillusioned with both the X-Men and X-Factor, Havok teamed up with the Black Beast, the Beast's evil counterpart from another timeline. Together they founded a team of mutant terrorists called the Brotherhood. However, Havok did not truly become a terrorist; he joined the Brotherhood only in order to stop the Black Beast's sinister plans. Recently, in an attempt to stop a time-traveller named Greystone from returning to the future, Havok was believed to be killed. Instead, his essense was transported into an alternate timeline version of himself. In this timeline, he and his wife, Madelyne Pryor, lead The Six and have a son named Scottie. He is now deciding if he wants to remain in this reality or find a way home.