The screech of a bird echoes across the swampland. The nocturnal creature swoops above your head--so close that you feel the whisper of its wings against your face. You decide that it is better to face any foe by firelight than fall victim to an unseen attack. "I see your point," you say. "You may light a fire." Before long, a small fire crackles inside the circle of rocks. Its orange light shines across the clearing. From the corner of your eye, you spy a shadow of movement.

At first, you think it''s just the light playing tricks on you. Then you see it again, a slithering black shape against the trees. You draw your sword. Iolaus leaps to his feet and scrambles backward. "What is it?" he squeaks. "Our enemy." The long shadow rises, and you see it clearly in the firelight. It is a thick, reptilian neck.

At its end is the head of a serpent, unlike any you''ve seen before: pointed snout, black fangs, yellow eyes. The Hydra stands almost 20 feet tall. As it steps forward from the trees, many more of its heads emerge. There are nearly two-dozen of them. Each neck slithers in a different direction. "Behind me," you say under your breath. Iolaus cowers in your shadow. The Hydra lashes out with one head, opening its black mouth wide and striking.

You reach behind you, clutch Iolaus by the arm, and dart left. The beast''s jaw snaps shut in the space you just abandoned. Without a second thought, you swing your sword and slice the serpent''s head from its neck. It falls to the dirt and rolls out of sight. The creature screeches in anger and pain. The neck squirms back and forth, but it does not bleed. Instead, a pulsing mass of muscle emerges from the wound. The mass splits, grows, and shapes itself into two new heads.

Behind you, Iolaus gasps. You sense his fear and can tell that he is about to flee. You grasp his wrist and look into his eyes. "Calm yourself. I will make sure you''re safe." Iolaus nods and whispers, "I trust you." The creature steps out from the trees. It has four squat legs, like those of a great lizard.

Beneath its feet, the edge of the clearing is nothing more than a pile of bones. They snap and crunch under the weight of the beast''s every step. Iolaus grabs a thick branch from the edge of the fire and wields it as a weapon. Its end burns red with flames, and the nearest Hydra head recoils away from it. This gives you an idea. "Iolaus, keep your torch ready," you command. "I will need your help." Iolaus nods as the torch shakes in his hands.

You ignore his fright and advance on the nearest head. The Hydra strikes. As before, you dodge it. Again you slice the head from its neck. This time, though, you grasp the wriggling neck and drag it to Iolaus. "Seal the wound with fire," you shout. "Quickly!" Squeezing his eyes shut, Iolaus places the flaming torch against the serpent''s wound. It sizzles and smokes.

The beast roars from this fresh pain, and the Hydra''s neck tries to pull itself free, but you do not let it. Iolaus draws back his torch. The neck is burned and blackened, and no new heads emerge. "It worked," Iolaus says. "We shall make quick work of this serpent," you say with a smile. You swing your sword again and attack the creature. One by one, you hack the heads off the Hydra and seal the neck with your companion''s torch. When the flame sputters and begins to die, Iolaus draws out a new log from the fire.

Soon, there are just two heads remaining, including the immortal head. It is different from the others: larger, with great nostrils that flare with each breath. The beast is wounded. Its movements are slow and labored. The immortal head slithers near, close enough that one mighty swipe could end the battle. "Hercules, behind you!" Iolaus cries. You turn in time to see a new foe at the far side of the clearing. It is a giant crab with eight long legs.

It scuttles toward you, opening and closing its sharp, curved claws. "We must have angered Hera," you reply. "She has sent a new creature to distract me from my labor." The crab charges directly toward Iolaus. Will you have enough time to defeat the Hydra before the crab attacks your companion? Or should you turn your attention away from the Hydra and attack the crab? What will you choose to do?.