A recurrent theme of the stories was that one of the ship's science officers gives a warning of danger, but is ignored and always ends up having to save the crew by himself.
Although obscure today, the stories were enormously influential; to the point that some of the creatures van Vogt invented have been openly imitated, most notably the telepathic, cat-like Coeurl (which became a recurring monster in the Final Fantasy series, as well as the inspiration for the Displacer Beasts from Dungeons & Dragons) and even the xenomorphs from Alien might have been based on van Vogt's work (he certainly believed so).
Tropes in the stories:
- And I Must Scream:
- Ixtl's human victims are paralyzed with its eggs inside them, waiting for the hatchlings to eat their way out. The doctor extracts the eggs in time and the paralysis wears off.
- The Ixtl itself, the last survivor from a dead universe, comes across the Space Beagle after quadrillions of years floating aimlessly through space. And it's subjected to this fate once more at the end of the story.
- The Bait: The Ixtl has been abducting people to serve as hosts for its eggs, so the crew act as bait to lure it into an ambush of forcefields and atomic disintegrator rays. Unfortunately a crewman in the line-of-fire panics and, instead of throwing himself to the ground, opens fire on the weapons crew. This ends up killing a whole bunch of people and tips off the Ixtl as to their plans. The captain had advised the "bait" not be armed for exactly this reason, but was turned down.
- Beware the Mind Reader: Riim society is stagnant because everyone can read everyone else's mind. As a result, they can't cope with change well, like the existence of extraterrestrial life.
- Beware the Quiet Ones: Dr. Grosvenor has no men under him and is in charge of a branch of science that no-one takes seriously, yet it's pointed out that he's probably the most dangerous person on the ship. This is shown when he decides to take over Space Beagle single-handedly, against a thousand men who have already defeated the Coeurl and Ixtl.
- Bold Explorer: Most of the crew of the Space Beagle, especially Director Morton, the head of the expedition. (The protagonist, Elliot Grosvenor, is along as more of a trouble-shooter.)
- Brainwashing for the Greater Good: For some background, everyone on the expedition (except the crew) was a scientist, all from different schools of thought. Grosvenor, the main POV character, studies "nexialism", which is a vague generalist overview of all the sciences (as opposed to specializing in one). His view is presented as the superior, and only, way to study science (i.e., specialists are always wrong and narrow-minded, generalist views are best). Nobody listens to his warnings of danger, and nobody signs on to Nexialism, so eventually he hypnotizes the entire crew through the ship's PA system to force them to turn to Nexialism. It works, and by the end of the book all the ship's scientists become Nexialists and learn from him. In fairness, the issues are a bit more serious than people not being Nexialists. The Space Beagle's crew are splitting up into competing factions, endangering the long-term safety of the ship, and in the last story an Eldritch Abomination is threatening all life in the universe.
- The Captain: Downplayed; while he's in charge of operating the Space Beagle, Captain Leeth is not in charge of the expedition itself, so doesn't take the foreground as later spaceship captains would.
- Cassandra Truth: Kent insists the Coeurl is dangerous and should be killed instead of being brought on the ship for study. It's not that he's ignored; it's just that the others underestimate the Coeurl's abilities and intelligence.
- The Cycle of Empires: Korita uses this theory to speculate on the motives (and future actions) of the various aliens they encounter. He postulates that the current human civilisation is in the 'winter' stage.
- Chromosome Casting: The crew is entirely male, with their sexual urges repressed by drugs.
- Emotions vs. Stoicism: Grosvenor and Kent have something of a The Spock vs. The McCoy vibe going on. Grosvenor once asks what Kent's appeal is to everyone and is told that his flaws make him seem more human, so people can identify more with that than Grosvenor's detached professionalism.
- Eldritch Abomination:
- Ixtl, an Ultimate Life Form that can survive for millennia in outer space and may have survived the destruction of its own universe in a Big Bang-type event. It can adjust its own atomic structure and is impervious to anything short of an atomic Disintegrator Ray.
- Anabis, a galaxy-sized Energy Being that feeds on the death of living beings — in other words, a Will-o'-the-Wisp the size of the Andromeda Galaxy.
- Energy Weapon: The radiation emitted by the vibration pistols and crew-served atomic disintegrators is invisible, so a 'tracer beam' is used for aiming. There's also reference to the smell of ozone and the potentially lethal effects of secondary radiation from a near miss by a disintegrator beam.
- First Contact Team: The crew of the Beagle.
- Fluffy the Terrible: The Coeurl is referred to as "pussy" due to its panther-like appearance.
- Hate Plague: The Riim attempt telepathic contact with the Beagle but inadvertently unleash everyone's inner inhibitions, causing them to all turn on each other.
- Have a Gay Old Time: There's lots of talk about "pussy" (the catlike Coeurl) and "vibrators" (the nonlethal weapons carried by the crew).
- Hostile Terraforming: Anabis, a galaxy-spanning consciousness that has terraformed all planets in its own galaxy by ripping a piece of its planets surface off and sending to to the target planet through hyperspace (called junglescaping).
- A House Divided:
- Director Morton finds himself being challenged for leadership by Kent, the head of the chemistry department. Several expeditions have been lost because they broke into disputing factions, and Grosvenor was put on board to attempt to avert this.
- The Riim's hypnotic influence divides the crew into warring factions based on hidden resentments: scientist vs. military, and the Morton vs. Kent factions.
- Ignored Expert: Dr Grosvenor is the lone nexialist (a scientist whose specialty is nonspecialization) in the crew. He's younger than the other department heads, manages no personnel, and no-one really knows what Nexialism is anyway — at the start of the book he even has to listen in on other people's Comm Links because he's not been included in the comm circuit for department heads. He gradually starts to win people over as he proves himself useful against each Monster of the Week, but then the Director dies and Kent replaces him. Kent has already taken a dislike to Grosvenor for opposing him in the election.
- Immune to Bullets: The Coeurl and Ixtl are immune to vibration guns, though not an atomic disintegrator ray — unfortunately, firing one inside the ship is dangerous in itself.
- Intangibility: Ixtl can not only change its atomic structure to pass through walls or the floor, it can do the same with any object it's carrying, enabling it to abduct humans at leisure.
- Intelligent Gerbil: The panther-like Coeurl and a species of telepathic alien birds called the Riim.
- Inertial Dampening: Anti-acceleration has made intergalactic travel possible.
- It Can Think: The crew bring the Coeurl on board the Beagle in the belief that it's a dumb animal, or at most an intelligent species that's reverted to a primitive state. Unfortunately it's as intelligent as they are. It only went on board the spacecraft because it's hunted all the prey in its area to extinction.
- Locked Room Mystery: The Coeurl kills several members of the crew and returns to its locked cage, which it can easily unlock with its control of electric fields.
- Made of Indestructium: The resistance metals that make up the outer hull are the only thing that Ixtl can't pass through. An armored suit is constructed out of the material, but as the material is so difficult to work they only have time to make a few.
- Meaningful Name: The title is an obvious reference to the HMS Beagle, the ship whose voyage of exploration included Charles Darwin, as the story has a similar discovery-of-new-species theme.
- Never Give the Captain a Straight Answer: Inverted; Captain Leeth calls Grosvenor to his location without giving details. He discovers the plan to kill the Ixtl has gone disastrously wrong causing the death of Director Morton and others, information the captain wouldn't want broadcasted for morale reasons.
- Nice Job Breaking It, Hero: After Morton wins the election by default (his rival Kent is injured) Grosvenor suggests that Morton name Kent his successor to defuse tension on board the ship. Unfortunately Morton is killed later on and so the Beagle falls under the control of a man who's already taken a dislike to Grosvenor.
- Omnidisciplinary Scientist: Grosvenor falls somewhere between this and The Spock. He isn't a master of every branch of science, but his training in Nexialism (which he describes as "applied whole-ism") gives him a middling-good understanding of all the physical sciences. He even knows something of psychology, including several ways to hypnotize humans and manipulate their emotions.
- Panthera Awesome: The Coeurl.
- Passive-Aggressive Kombat: Grosvenor publically questions whether Kent is a suitable candidate for leader, then finds that Kent's minions have set up a food processing laboratory in his offices. He retaliates by playing them subliminal learning tapes so Kent's minions will know as much about chemistry as Kent does.
- Patchwork Story: A "fix-up" of van Vogt's magazine stories set on the Space Beagle.
- Playing Sick: Grosvenor takes a pill to give himself the flu so he has an excuse to quarantine himself in his office, which he's Booby Trapped with various defences.
- Protagonist-Centered Morality: When people do not listen to, agree with, or vote in favor of Grosvenor, he brainwashes and hypnotizes or imprisons them to get what he wants. This is viewed as a good thing because he is "right".
- Puny Earthlings: Because it doesn't feel threatened Ixtl makes the mistake of abducting humans for reproduction instead of concentrating its efforts to Kill All Humans that it doesn't need for this purpose. It realises too late that Humans Are Warriors.
- Reasonable Authority Figure: Director Morton who is in charge of the expedition is a natural politician. His successor Kent unfortunately is not.
- Scientist vs. Soldier: Discussed but downplayed; except when the Riim start messing with peoples heads and open war breaks out, Captain Leeth and his men stick to running the ship and let the scientists argue over what they're going to do. When overruled by Director Morton, Leeth doesn't buck the chain of command.
- Starship Luxurious: The Space Beagle is an intergalactic spaceship with a crew of a thousand.
- Time Abyss: The crew theorize that Ixtl is a creature from a previous incarnation of the universe, and had been drifting in space since before the Big Bang until it encountered the Beagle.
- Trapped-with-Monster Plot: The encounter with Ixtl was one of the prototypes for this kind of plot in science-fiction media.
- Villain Protagonist: The encounter with Coeurl is told chiefly from its own POV.
- Weaponised Teleportation: Anabis teleports wild beasts onto the control room of the Space Beagle, and terraforms planets by teleporting large parts of the landscape from one planet and dropping it on another.
