[Note: this story fits best between pages 8 and 9 of WEREWOLF BY NIGHT #17]
Part One: She Stalks in Beauty Like the Night - On a secluded shore on Mexico's Pacific coast, Jack Russell awaits his transformation under the full moon. His reverie is broken by the appearance of a young woman being chased. Rushing to her aid, he is knocked cold by two Hydra soldiers who attempt to grab the woman. However, she transforms, calling herself "Tigra". She overcomes the goons just as Jack becomes the Werewolf and attacks her. Their scuffle is ended when a "sonic shatter cone" launched by Hydra agents explodes, stunning them. Tigra is captured and the Werewolf is left behind.
Part Two: A Warrior Reborn! - The next night, in an underground lab, the caged Tigra watches as Hydra agents dismantle the place looking for something called the "Final Secret". She recalls the events leading to this point. As Greer Nelson, under the aegis of scientist Dr. Joanne Tumolo, she became the crimefighter known as the Cat. A day earlier, she foiled a kidnap attempt of Tumolo by Hydra, but was shot with a radiation pistol. To save Greer's life, Tumolo revealed herself to be from a race of cat people, and that Greer would live if she became one of them. In the Cat People's lair in a cave in Mexico, Greer underwent the ritual that transformed her into Tigra. Moments later, Hydra goons burst in and captured everyone but Greer, who escaped in human form. Now, the Hydra goons intend to beat the location of the Final Secret out of Dr. Tumolo.
Part Three: "Some Say the World Will Die...!" - On the beach, under the second full moon, Jack has transformed again, and he follows the trail of Tigra, with whom he feels a kinship. Finding the lab, the Werewolf frees Tigra, and the two defeat her captors. Tumolo then leads them to the cell where the Cat People are being held, fighting more Hydra agents along the way. As they free the captives, Hydra reinforcements arrive, guns blazing. Desperate, Dr. Tumolo turns a wheel that releases a gas deadly to humans. The Hydra gunmen fall, while the Werewolf, Tigra, Tumolo and the Cat People leave the cave. Outside, a sorrowful Tumolo explains the Final Secret was released only once before: then, mankind had named it the Black Plague. Now with the crisis passed, the Werewolf tugs at Tigra to run with him, but she transforms to Greer Nelson. Confused, he lopes away, as behind him, Greer again becomes Tigra, unable to maintain her human form any longer.
This issue also includes the story, "Where Walks the Werewolf", an unrelated tale reprinted from CREATURES ON THE LOOSE #13.