Rush's first true epic and their first multi-part suite — the song that proved they could handle ambitious, extended compositions and paved the way for the side-long epics that would follow. It's divided into four sections: "At the Tobes of Hades," "Across the Styx," "Of the Battle," and "Epilogue."
The origin story is wonderfully absurd. Rush roadie Howard Ungerleider stayed at manager Ray Danniels' house, where Danniels' German Shepherd growled menacingly at him while a tiny dog tried to jump on him. Ungerleider told the band and they found it hilarious. Geddy Lee later recalled: "We must have been high one day, imagining a song about these two dogs. And then Neil went ahead and wrote it." Lee would later call it "a joke that got out of control."
Peart took the silly premise and spun it into a fantasy battle narrative, with By-Tor as the villain and the Snow Dog as the hero. The middle "battle" section features wild, chaotic instrumental passages with Lifeson using distortion and effects to create an almost cinematic soundscape. Peart himself liked the mysterious first section title best — "At the Tobes of Hades" came from a phrase his friend's father used to say, and its meaning remained unclear even to the band.
On the original vinyl pressing, the chimes at the end of the song continue into a locked groove, playing indefinitely on manual record players — a fun hidden detail. By-Tor would return as a character in "The Necromancer" on Caress of Steel. The song became a fan favorite and was performed live well into the band's later years, including the R40 farewell tour.