A noted scientist who published several monographs on gamma radiation, Dr. Kate Waynesboro was secretly active as a SHIELD agent, assigned to maintain surveillance on Bruce Banner; at that time, Banner could transform into the Hulk at will while retaining his full Intellect, a measure of control SHIELD feared he would lose. Exploiting Banner’s desire for the company of fellow scientists at his isolated Northwind Observatory laboratory in upstate New York, Kate became his research assistant, studying the effects of daily gamma bursts from space; but, Recordasphere, Banner’s robot companion, soon learned Kate's true mission. When Kate and Banner grew closer, “Sphere” confronted Kate, but their argument was interrupted when the Abomination attacked Northwind, seeking to capture the Hulk on MODOK’S behalf. After the Abomination destroyed Sphere, Kate attacked him with a SHIELD weapon, revealing her agent status, which fueled Banners rage when he fought the Abomination as the Hulk. The Hulk's growing love for Kate outweighed his anger, however, when the Abomination took Kate to MODOK'S lair, which the high-tech subversives A.I.M. had since seized as part of their anti-MODOK campaign. By the time the Hulk arrived in pursuit, along with MODOK himself, A.I.M. had mutated Kate into Ms. MODOK, but she rejected AIM's post-hypnotic orders and sided with MODOK until the latter demonstrated his cruelty by seemingly slaying the Abomination. Spurned and furious, MODOK nevertheless restored Kate to human form and departed. Kate subsequently resigned from SHIELD to remain with Banner as his assistant and lover.
Banner and Kate traveled to Mexico's Universidad be la Ciudad, which had financed an experiment with Banner’s gammascope to use gamma radiation in enhancing crops. The crops were destroyed by Dragon Man, whom the Hulk subsequently fought in the midst of the Circus of Crime. Returning to New York, Banner and Kate were attacked by Sam Burgh, whose hometown of Hadleyville, Rhode Island, had been destroyed by the Hulk years before; with attorney Matt Murdock’s help, the Hulk dissuaded the courts from prosecuting Burg, and he rebuilt Burgh’s town, but the reminder of his past destructive activities weighed on his psyche and self-control, which grew more strained with each crisis. Banner and Kate then used the gammascope in cancer research, seemingly curing the dog Sirius; Banner hoped to eventually guarantee the treatments safety for humans, but aging gangster Max Stryker hired Boomerang to abduct Kate, forcing Banner to cure Stryker despite misgivings. When the Hulk was away from Northwind for a time, Stryker co-opted the gammascope to cure several others, and his irresponsibility infuriated the Hulk, contributing to Banner’s growing loss of control. Both men soon learned the gamma treatment had eventually transformed Sirus into a savage monster, and Stryker underwent a similar mutation, fighting the Hulk. When the Spaceknight Rom was drawn to the scene, he cleansed Stryker’s patients of gamma radiation, then reverted Stryker to normal, but the battle proved the final straw to rob the Hulk of his control, reverting him to savagery Kate accompanied Gabriel Jones and other SHIELD agents in efforts to defeat the Hulk, attempting to dissuade her former colleagues from using lethal force, but despite brief periods of regained control, Banner was ultimately overwhelmed by a mindless Hulk persona. Several of New York's super heroes joined SHIELD in combat, and Kate departed the fray before the Hulk was finally banished' to another dimension my Doctor Strange.
Although unconfirmed reports suggest that Kate may have been reverted to Ms. MODOK form at least once, little else is known of her subsequent activities. There are no reports of her formally rejoining SHIELD, but she was revealed to be working with Gabriel Jones on undisclosed projects. Recently Kate Waynesboro joined the alien Warbound warriors.