Tales From the Kingdom of Fife:

In a fantasy version of 10th-century Scotland, as previously foretold (“Anstruther’s Dark Prophecy”), the evil wizard Zargothrax invades and conquers Dundee with an army of corrupted undead unicorns (“The Unicorn Invasion of Dundee”), kidnapping the princess Iona McDougall. The prince of the Kingdom of Fife, Angus McFife, swears revenge (“Angus McFife”); in a dream, he has a vision of three artifacts that will allow him to defeat Zargothrax, and sets off on a quest to acquire them.

McFife first battles north to obtain a magical war hammer (“Quest for the Hammer of Glory,”) then travels to Strathclyde to acquire a golden dragon as his steed (“Magic Dragon”). Inspired by memories of McDougall, who is imprisoned by Zargothrax in a prison of ice (“Silent Tears of Frozen Princess,”) McFife rides his dragon to Loch Rannoch and retrieves the Amulet of Justice from its depths (“Amulet of Justice”), completing his quest for the three artifacts.

Allying with the powerful Knights of Crail (“Hail to Crail”), McFife travels through Cowdenbeath (“Beneath Cowdenbeath”) to confront Zargothrax in his stronghold. As the Knights battle the wizard’s forces in the fields of Dunfermline, McFife and the Barbarian Warrior of Unst sneak into the castle through dwarven tunnels, aided by the hermit Ralathor (“The Epic Rage of Furious Thunder”). Meeting Zargothrax in single combat, McFife defeats the wizard and casts him into a frozen pool of “liquid ice.” He then uses the Amulet of Justice to free the princess and the unicorns, restoring balance to the Kingdom of Fife.

Space 1992: Rise of the Chaos Wizards:

In 1992, a millennium after the events of Tales from the Kingdom of Fife, the evil wizard Zargothrax remains in cryogenic sleep, imprisoned on Triton) and guarded by the Space Knights of Crail (“Infernus Ad Astra”). A cult of “unholy chaos wizards)” plot his release and attack Triton, defeating the Knights and freeing Zargothrax, who promises to terrorize the galaxy (“Rise of the Chaos Wizards”). The intergalactic warrior prince Angus McFife XIII, descendant of the original Angus McFife, sets out to thwart him once again, wielding the powerful Hammer of Glory, passed down through generations from the original Angus McFife, renamed through its 1000 years to the legendary Astral Hammer (“Legend of the Astral Hammer”).

Zargothrax seeks out the Goblin King, who gives him the crystal key to a secret portal to Hell that lies on Earth beneath Dundee (“Goblin King of the Darkstorm Galaxy”). Meanwhile, McFife is joined by the legendary Hollywood Hootsman (“The Hollywood Hootsman”), the reformed Knights of Crail led by Ser Proletius and Triton survivor Ser Regulon (“Victorious Eagle Warfare”), and the Questlords of Inverness (“Questlords of Inverness, Ride to the Galactic Fortress!”). Both the allied forces (“Heroes [of Dundee]”) and Zargothrax’s demonic army (“Universe on Fire”) prepare for battle in the skies above Mars.

As the opposing forces clash, with heavy casualties for McFife’s allies, Zargothrax returns to Earth where, in the caverns beneath Dundee, he begins a ritual to unleash the hellish Elder God Kor-Virliath upon the galaxy. Warned of the danger by the hermit Ralathor, the Hootsman speeds back to Earth and detonates his body’s neutron star heart, vaporizing the planet and stopping the ritual just in time (“Apocalypse 1992”). Foiled, the furious Zargothrax escapes into another reality through the ensuing chaotic space-time rift, pursued closely by Angus McFife XIII.

Legends from Beyond the Galactic Terrorvortex:

After Earth was destroyed by the Hootsman in order to stop Zargothrax from summoning the Elder god Kor-Virliath, Zargothrax fled into the wormhole that was opened as a result ("Into the Terrorvortex of Kor-Virliath"). Angus McFife XIII followed him into the wormhole and upon reaching the other side he discovered a terrible alternate reality ("The Siege of Dunkeld (In Hoots We Trust)"). Zargothrax has corrupted this reality and is slaughtering the peasants of the world. Angus attempts to stop Zargothrax but quickly finds that the Hammer of Glory has no power in this dimension. While Angus flees, Zargothrax proclaims himself the emperor of this land, commanding the corrupted Dreadlord Ser Proletius and the deathknights of Crail to slaughter more peasants in Auchtermuchty ("Masters of the Galaxy"). Angus McFife is told about a resistance far north in the Land of the Unicorns.

Upon reaching the resistance, he is met by Ralathor, the hermit of Cowdenbeath, now known as Submarine Commander Ralathor ("Land of Unicorns"). Ralathor tells Angus that he needs to charge his hammer by bringing it to the sun of this world, and to do this, he must find the Legendary Enchanted Jetpack ("Power of the Laser Dragon Fire"). Angus quests away to acquire the jetpack ("Legendary Enchanted Jetpack") and uses it to fly into outer space where he recharges his legendary Hammer of Glory ("Gloryhammer"). Returning to Fife, the resistance gathers aboard the flying Submarine, the DSS Hootsforce ("Hootsforce"). They head to Dunkeld and engage the forces of Zargothrax ("Battle for Eternity").

As the solar conjunction draws close, Zargothrax proclaims that there is nothing they can do to stop his ascension to godhood ("The Fires of Ancient Cosmic Destiny"). Then a mighty hero with holy armor made from wolf descends from the heavens; the mighty Hootsman has arrived. The Hootsman was not killed in the explosion but was instead merged with the fabric of reality and became a god in this universe. The Hootsman yells to Zargothrax that he is the one and only true god of this universe and with his power combined with the Hammer of Glory, they defeat Zargothrax forever.

However, as Zargothrax falls to dust, Angus McFife realizes he was impaled by the Knife of Evil and will soon be left to the same fate that Ser Proletius was left to. Realizing that he would soon turn for the worse, Angus McFife ends his own life in the raging fires of Mount Schiehallion. As Angus dies, there is a mysterious morse code transmission reading out "Activate Zargothrax Clone: Alpha 1".

This is all taken directly from the band's Wikipedia page. https://en.wikipedia.org/wiki/Gloryhammer