What happens when you hand a teenager the keys to saving the solar system from sun-stealing aliens? If you grew up devouring pulp science fiction in dusty library corners like I did, you already know the answer: pure, unfiltered adventure.
Donald A. Wollheim's Secret of the Ninth Planet dropped in 1959, right when America was racing toward the stars and every kid with a telescope dreamed of commanding their own spacecraft. Burl Denning is that kid—a high school student thrust into humanity's most desperate hour when an alien race starts siphoning energy from our sun, threatening to trigger a nova within two years. The premise is gloriously absurd by modern standards, yet there's something refreshing about its earnest optimism. This is science fiction from an era when space meant possibility, not existential dread.
I listened to Richard Kilmer's LibriVox narration during a week of early morning commutes, and I'll be honest—the experience was complicated. Kilmer reads with the kind of measured clarity that would've been right at home on educational filmstrips from that era. His pacing is steady, his diction precise, and you'll never miss a word. For a book aimed at younger readers, this straightforward approach makes sense. The solar system tour Wollheim provides—with the Magellan visiting planet after planet to destroy alien installations—becomes almost instructional, and Kilmer delivers it like a patient teacher walking you through a diorama.
But here's the rub: when Burl and his crew face genuine peril, when alien technology threatens to end everything, Kilmer maintains that same even keel. The narration stays emotionally flat even during sequences that should have your pulse quickening. I found myself mentally adding exclamation points where his delivery suggested periods. It's a strange disconnect—reading about desperate space battles while the narrator sounds like he's describing the weather.
This isn't necessarily a dealbreaker. Some listeners praised Kilmer's clarity and found his relaxed tone fitting for the material's vintage character. Others called it "appallingly read" and "too relaxed for what was happening." Both perspectives have merit. If you're approaching this as a nostalgic artifact, a time capsule of juvenile sci-fi from the Sputnik era, Kilmer's delivery becomes part of the charm. If you're expecting the dramatic punch of contemporary audiobook narration, you'll likely find yourself frustrated.
Wollheim: Editor-Turned-Worldbuilder
Wollheim himself deserves recognition here. Before he became one of science fiction's most influential editors and publishers—the man who helped launch countless careers and shaped the genre's trajectory—he wrote accessible adventures like this one. His prose is clean and unpretentious, focused on forward momentum and planetary wonder. That same drive for propulsive storytelling shows up in Clash of Kings: A Song of Ice and Fire: Book Two, though Martin's world-building operates on a vastly different scale. The scientific details here are dated (this was written before we knew what we know about Venus and Mars), but that datedness becomes part of the appeal. You're experiencing the solar system as 1959 imagined it—mysterious and conquerable.
The audio quality is solid, typical of LibriVox's volunteer productions. No distracting background noise, no volume inconsistencies. A clean recording that does its job without fanfare.
Roll for Initiative (Or Maybe Don't)
Who should spend five and a half hours with Burl Denning? Parents looking for clean adventure content for younger listeners will find this fits the bill—the violence is mild, the language appropriate, the themes straightforward. Vintage sci-fi enthusiasts who want to hear these old paperbacks in audio form will appreciate having the option. And anyone curious about what science fiction sounded like before we actually walked on the moon might find genuine value here.
But if you need your narration to match the energy of the story, if monotone delivery pulls you out of a narrative, this might not be your ride. The gap between Wollheim's exciting plotting and Kilmer's subdued reading creates friction that some listeners won't be able to ignore.
I kept returning to this audiobook despite my reservations, partly because the story's earnest charm won me over, partly because there's something meditative about Kilmer's unhurried pace during a morning commute. At 1.25x speed, the pacing felt more natural, the flat spots less noticeable. If you decide to give this a shot, that speed adjustment might be worth trying.
A Relic Worth Dusting Off
Secret of the Ninth Planet is a relic in the best sense—a window into how we once dreamed about space, delivered by a narrator who treats the material with respect if not excitement. It won't blow you away, but it might remind you why you fell in love with science fiction in the first place.
