Leo and Sirius are age-old enemies. In every three hundred years, malicious Sirius will exercise its evil power to turn human beings into werewolves. They would then go and hunt for blood to be used at the altar of Sirius. Righteous leader YIP LING SIU of the Sun Castle leads the search for the Leo-stone to subdue the evil power of the werewolf. He claims that the leader of Moon Castle, HA CHIN PANG, is the werewolf, and starts the pursuit against him. Horoscopes TIN HANG remains skeptical of the claim. Pursued by People, CHIN PANG sends away his daughter CHI-TSING. In the combat against LING',:'SIU, he falls down a cliff. TIN-HANG is attacked by mysterious agents, and is forced to go on a journey to evade the pursuits. CHI-TSING is rescued by a couple and is brought up by them in the Haunted Valley. Eighteen years passed. PAK-LUNG is taught by his father horoscopy. A meteor slides across the sky……

CHI TSING is taught martial art by a masked man. When the Leo-stone appears, CHI TSING is asked by him to set off and search for the stone.CHI TSING meets TIN HANG and PAK LUNG on the way. They see traces of werewolf and start investigation. Later on, they find out that it is YIP LING-SIU's daughter PING's impersonation. She wants to scare everyone off so that she could possess the stone for herself. The stone has earlier been taken by Craftsman LO CHIU. A trap has been set. TIN HANG sacrifices his life to rescue PAK LUNG, CHI TSING and YIP PING.YIP TSING hurries back to the Sun Castle to receive her aunt TSING FA and cousin TIT CHU. TSING FA has a wicked plan to usurp the Chieftain status from YIP LING SIU. She has YIP PING take some ageing poison. YIP PING ages quickly, but she refuses to yield the Chieftain plaque to her aunt. YIP LING SIU is invigorating himself in a closed Chamber.

Cousin TIT CHU leaves the castle angry with his mother's despiteful behavior. He meets TIN LUNG and CHI TSING and tells them everything. They hurry to the Sun Castle. After seeing YIP PING, they resolve to have CHI TSING go back to the Haunted Valley to get healing medicine. The couple that bring up CHI TSING is masters in medicine. Their medicine is grabbed by the lord of the Valley NGO KONG, who threatens to kill CHI TSING. PAK LUNG arrives and starts a fight with NGO. He-succeeds in getting back the medicine.

YIP PING recovers from her ageing disease with the medicine from PAKLUNG and CHI TSING. YIP then summons her people to pursue her aunt CHING FA and TIT CHU. The werewolf appears and attacks the mother and son. TIT CHU is poisoned and becomes a werewolf at full moons. LING SIU knights PAK LUNG, and sends-him to seek for the Leo-stone with PING. Out of jealousy, PING accuses CHI TSING an evil agent coming from the notorious Haunted Valley. CHI TSING leaves the castle in great anger. Back in the Haunted Valley, CHI TSING is forced by the master to produce the youth potion. TSING FA comes to the Haunted Valley to seek help from the couple who are medical experts.

PAK LUNG and YIP PING pay a visit to LO CHIU to ask for the Leo-stone. They have to surmount ordeals and traps before LO would receive them. At this time, CHI TSING has brought along TSING FA to seek from LO some herbal medicine grown out of the Leo-stone to cure TIT CHU's ailment. CHI TSING wires the favor of LO and secures the herbal medicine As TSING FA greedily seeks to grab the Leo-stone for herself, a strange phenomenon happens. Three stars align and the Leo-stone radiates with glaring lights that scares away TSING FA. PAK LUNG and the others secure the Leo-stone and take it back to the Sun Castle. CHI TSING is instructed by her master to steal the Leo- stone from the castle.

TIT CHU falls down a cliff and is rescued by a woman ninja SHUM TIN MUI. They get to know each other's history and quickly fall in love. CHI TSING is caught by PAK LUNG and YIP PING of stealing the Leo-stone. She leaves them with great shame. CHI TSING returns to the Haunted Valley. She is voted the new leader of the valley. However, she remains depressed as her thoughts are still with PAK LUNG. PAK LUNG and YIP PING return to the Sun Castle and discover that the Leo-stone is counterfeit. They suspect LO CHIU has the real stone and decides to go to the Haunted Valley to get it.

TIN MUI hurriedly leaves home with TIT CHU as her fiance YAT LONG returns. On their way they meet TSING FA. TSING FA discovers that TIN MUI is her enemy's daughter. In TIT CHU's absence, she tries to kill TIN MUI with a poisoned knife. TIT CHU returns to see TIN MUI injured: In great indignation, he leaves with her. They meet PAK LUNG and YIP PING on their way to the Haunted Valley. PAL LUNG offers some medicine to TIN MUI that could stop temporarily the poison from spreading. CHI TSING finally discovers that the masked man is actually her father CHIN PANG and who has hidden all these years to evade the pursuit from people who mistakes him as the we wolf.

TIT CHU seeks medicine from YAT LUNG to heal TIN MUI. YAT LUNG suggested TIT CHU to secure the Leo stone for exchange. PAK LUNG and YIP PING arrive at the Haunted Valley and ask CHI TSING for the Leo-stone. At this point, TIT CHU arrives too, begging for the Leo-stone. As they get into arguments and fights; the three stars align again, causing the Leo-stone to be spitted into two. TIT CHU gets half and YIP PING gets the other half. YAT LUNG gets the Leo-stone from TIT CHU and uses it to open the secret door of a treasure Chamber that he discovers. TIT CHU and CHIN FA follows him. The three are trapped inside, with the Leo-stone outside the door.

TIT CHU discovers two precious weapons and succeeds in using it for exchange of the medicine for TIN MUI. CHI TSING follows TIT CHU and finds that he is trapped inside the cave. She uses the Leo-stone to open the door. YAT LUNG grabs the Leo-stone and hurt CHI TSING with a poisoned dart. PAK LUNG and YIP PING pass by and witness the scene. PAK LUNG pleads with YIP PING for the herbal medicine that can heal CHI TSING. He promises to marry YIP PING as an exchange. On the wedding night, TSING FA arrives in time to stop the ceremony. She defeats YIP PING and cure SCHI TSING with the medicine from YAT LUNG. The injured YIP PING flees with the Leo-stone. She is discovered by NGO KONG, who is instructed by TSING FA to pursue her. YIP is assaulted by NGO. She swears to revenge on NGO and TSING FA. The three stars align for the third time. CHI TSING's Leo-stone turns into a bow, whereas the stone with YIP turns into a sword.

YIP PING returns to the Sun Castle and begs her father LING SIU to teach her more skills so that she could revenge on her own. LING SIU sacrifices his own life in passing on his skills to her.PAK LUNG learns of the death of LING SIU. He finds that the Leo remains bright, and concludes that PAK LUNG is not the werewolf. As he gathers people to launch attack against CHIN PANG, whom he believes is the real werewolf, he discovers that LING SIU is not dead, he is shown by CHIN PANG to LING SIU's grave and finds that it is empty.PAK LUNG and TIT CHU are discovered by YIP PING to be spying in the Sun Castle. She begs PAK LUNG to stay but is refused.

CHIN PANG meets LING SIU and learns of the story about his becoming the werewolf. Twenty years ago, in order to be the invincible master LING SIU sold his soul to the Sirius and becomes its slave. LING SIU resurrects and lobbies people to co-operate in the pursuit against CHIN PANG, who is framed to be the werwolf.YIP PING is shocked to see wolf hair growing out from her body. She learns then from LING SIU of his real identity. Having no other alternative, she vows to serve the Sirius too. LING SIU discovers that PAK LUNG attempts to steal the Leo-sword and starts a combat with him. PAK LUNG is seriously injured. CHIN PANG comes in time to rescue him, but he himself is sacrificed.

As YAT LONG gives the fiery pill to LING SIU, PAK LUNG grabs it quick and runs. He is then chased by LING SIU to a cliff. Knowing that he cannot beat LING SIU, He swallows the pill and jumps down the cliff. HEUNG YEE saves PAK LUNG and takes him home. Her father CHIN FUNG judges that PAK LUNG has been burnt seriously inside, and only the icy jade inside the cave of high mountain can heal. HEUNG YEE resolves to go and seek for the jade, despite her father's. objection. She meets CHI TSING, who has learnt of PAK LUNG's injury. They carry PAK LUNG to the mountain. With great difficulty., they succeed to kill the monster which guards the jade. However, HEUNG YEE is poisoned on the arm. Her father cuts it off to prevent the poison from spreading.

YIP PING has stayed in the Haunted Valley, pretending to have spitted with LING SIU. She revenges against TSING FA by blinding her eyes. To become the leader of the valley, she kills TIN MUI and NGO KONG. As PAK LUNG recovers, CHI TSING departs to go back to the Haunted Valley. She is ragouts learning the evil deeds that YIP PING does. She immediately sets off to find TIT CHU, who is keeping the Leo-bow. When she discovers TIT CHU, she finds that he has been stroke heavily on his head and is unconscious. TIT CHU regains his senses but has lost his memories.

HEUNG YEE is deeply devoted to PAK LUNG. When she overhears PAK LUNG vowing to love CHI TSING only, she decides to leave. TSING FA gropes her way to the Sun Castle to revenge against YIP PING. She grabs the Leo-sword which is stolen by YAT LONG under the instruction of YIP PING. YIP PING contrives the plan to force LUNG SIU to pass on the werewolf skills to her. TSING FA is tempted by the Sirius with werewolf skills to become its slave. TSING FA becomes a werewolf, to the great pain of her son TIT CHU. TSING FA would not listen to TIT CHU, but swears to use the skills to kill L.ING SIU.

With great difficulty, TIT CHU finally remembers where the Leo-bow is. As he is about to hand it to PAK LUNG, LING SIU and TSING FA arrive to grab it. A fierce combat begins. TSING FA loses and falls down the cliff. PAK LUNG and TIT CHU are wounded. A masked man comes in time to save them. TSING FA is rescued by the masked man. But she has been fatally wounded. In her dying breath, she asks TIT CHU to revenge for her. YIP PING co-operates with LING SIU only apparently. In the mean time, she is establishing her forces ready to go against LING SIU. She seduces YAP LONG into becoming her faithful subordinate. PAK LUNG discovers that the masked man is actually HEUNG YEE. HEUNG YEE bids goodbye to PAK LUNG and CHI TSING and wishes them happiness.

YIP PING declares war on PAK LUNG and CHI TSING, thinking that she is well-trained of the werewolf skills. To her surprise, she is totally powerless in confronting the two. YIP PING finds out from LING SIU that what she has from LING all this time is werewolf poison which is detrimental to her health. She is even imprisoned for her attempt to revolt against him. YAP LONG has been instructed by YIP PING to steal the Leo-sword. He meets CHIN FUNG and HEUNG YEE and is overpowered by the two. LING SIU leads a hunt against the Haunted Valley spreading the rumor that people there has got hold of the Leo-sword. The Valley people are fully prepared. As everyone arrives, they declare LING SIU the werewolf.

As his real identity is made known, he resolves to threaten other leaders to join him. Otherwise, they would be punished by the Sirius. CHIN FUNG uses the Leo-sword to force PAK LUNG to marry his daughter HEUNG YEEE. PAK LUNG refuses. CHIN FUNG leaves them in anger. LING SIU tries every evil mans to get back the Leo-sword, but are stopped every time by PAK LUNG with h-8 horoscope skills. PAK LUNG witnesses more and more people sub come to the evil force. He decides to have a duel with LING SIU with his Leo-bow.

PAK LUNG engages in a duel with LING SIU but finds leis Leo-bow no match of LING SIU's werewolf skills. At the critical moment, HEUNG YEE arrives with the Leo-sword which she begs from her father. The bow and sword combines to elicit great power. LING SIU is fatally wounded, but manages to escape. LING SIU loses all his werewolf skills. He is instructed by the Sirius to go up the Sirius Mountain to get new power directly from the Sirius. PAK LUNG wants to stop LING SIU from going up the mountain. Only CHIN FUNG's magic mirror can tell where the mountain is. CHIN FLING again demands PAK LUNG to marry HEUNG YEE. PAK LUNG is forced to agree.

HEUNG YEE is fatally wounded in the attempt to stop LING SIU from going up the mountain. In her dying breath, she blesses PAK LUNG and CHI TSING a happy life. YIP PING has YAT LONG kill CHIN FLING, who refused to use the magic mirror to locate the medicine for healing YIP PING. PAK LUNG decides to kill YIP PING to avenge for all his good friends that YIP has killed. But YIP declares that PAK LUNG has to absorb power from the Leo on the Leo Mountain in order to eliminate LING SIU and she knows the way to the Leo Mountain. PAK LUNG and LING SIU comes to a final duel. At the end, the righteous triumphs over the evil.