The Empty Door
by E.R. Mason
4.11 · 9 ratings
book · action-adventure · fiction · adult · sci-fi · invasion · fantasy · mystery · aliens · mlm · super-powered · romantic-love · paranormal · violent-conflict
The Empty Door: Similar series
Corsairs
by Ruby Dixon
4.04 · 140 ratings
dark · sci-fi · adult · fated-mates · outlaws · aliens · fiction · paranormal · multi-pov · space · alpha-mc · romance · kidnapping · book · steamy · slavery · action-adventure · humor · audiobook · friends-to-lovers
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Commonwealth Saga
by Peter F. Hamilton
4.11 · 138 ratings
adult · sci-fi · space-opera · fiction · audiobook · book · action-adventure · hard-sci-fi · space · military · first-contact · male-author · violent-conflict · epic · space-travel · aliens · mystery · futuristic · war · dystopia
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The Lost Fleet
by Jack Campbell
4.08 · 372 ratings
violent-conflict · book · audiobook · space · war · fiction · aliens · action-adventure · sci-fi · space-opera · space-travel · military · space-fleet · male-author · adult · politics · futuristic · exploration · nautical · first-contact
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Heechee Saga
by Frederik Pohl
3.84 · 154 ratings
action-adventure · fiction · hard-sci-fi · adult · space-opera · sci-fi · space · aliens · mystery · book · audiobook · exploration · first-contact · space-travel · classics · literary · invasion · ai · male-author · violent-conflict
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Freehold: Grainne War
by Michael Z. Williamson
4.02 · 69 ratings
book · war · fiction · space-opera · sci-fi · violent-conflict · space · adult · military · action-adventure · hard-sci-fi · first-contact · crime · female-mc · aliens · earth
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Echo Trilogy
by Lindsey Sparks
4.15 · 99 ratings
urban-fantasy · romance · book · time-travel · paranormal · fiction · action-adventure · historical-fiction · historical · magic · adult · supernatural · audiobook · myths · new-adult · urban · fantasy · sci-fi · gods · psychics
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Zoey Ashe
by David Wong
4.02 · 65 ratings
sci-fi · fiction · humor · action-adventure · super-powered · dystopia · book · adult · satire · crime · cyberpunk · horror · comedy · new-adult · female-mc · futuristic · audiobook · urban-fantasy · cats · male-author
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Autumn
by David Moody
3.89 · 122 ratings
zombies · fiction · monsters · horror · dystopia · action-adventure · adult · sci-fi · book · apocalyptic · season-autumn · post-apocalyptic · survival · male-author · military · epidemy · medical · supernatural · suspense · mystery
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Metahuman Files
by Hailey Turner
4.33 · 147 ratings
book · romance · action-adventure · fiction · adult · military · mlm · paranormal · lgbtq · violent-conflict · urban-fantasy · dystopia · war · steamy · suspense · audiobook · crime · futuristic · sci-fi · supernatural
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Spin Trilogy
by Chris Moriarty
3.78 · 32 ratings
fiction · action-adventure · hard-sci-fi · adult · space-opera · sci-fi · book · cyberpunk · space · transhumanism · ai · mystery · war · violent-conflict · singularity · cloning · aliens · robots · outlaws · lgbtq
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Battle Harem
by Isaac Hooke
4.00 · 28 ratings
violent-conflict · space · cyberpunk · adult · space-fleet · military · first-contact · space-travel · space-opera · soldiers · sci-fi · action-adventure · aliens · exploration · colonization · fiction · harem · book · invasion · humor
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Fractured Stars
by Lindsay Buroker
4.23 · 34 ratings
fiction · adult · space-opera · sci-fi · action-adventure · book · female-mc · space · galactic-empire · mystery · supernatural · aliens · colonization · exploration · animals · crime · slow-burn · romance · anthologies · invasion
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Black Ocean
by J.S. Morin
4.05 · 151 ratings
adult · military · space-opera · fiction · space · book · space-fleet · sci-fi · action-adventure · violent-conflict · magic · aliens · audiobook · urban-fantasy · space-travel · humor · crime · post-apocalyptic · outlaws · mystery
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Alien Raiders' Brides
by Vi Voxley
4.08 · 29 ratings
book · steamy · action-adventure · aliens · fiction · dark · sci-fi · paranormal · military · first-contact · adult · futuristic · kidnapping · romance · warriors · sexual-assault · alpha-mc · fated-mates · dystopia · other-world
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TekWar
by William Shatner
3.31 · 64 ratings
fiction · mystery · book · adult · sci-fi · action-adventure · dystopia · crime · cyberpunk · humor · hard-boiled · murder · kidnapping · heist · 21st-century · contemporary · law-enforcement · noir · male-author · substance-abuse
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Project Gleise 581g
by S.E. Smith
4.10 · 20 ratings
aliens · fiction · sci-fi · audiobook · military · adult · romance · book · action-adventure · violent-conflict · futuristic · steamy · soldiers · suspense · assassins · galactic-empire · political-intrigue · first-contact · invasion · dystopia
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Alien Adoption Agency
by Tasha Black
4.38 · 90 ratings
fiction · adult · book · paranormal · aliens · shapeshifters · romance · sci-fi · action-adventure · first-contact · new-adult · fantasy · insta-love · dragons · poc-mc · exploration · fated-mates · space-travel · monsters · violent-conflict
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Cyber Noir
by Jon Courtenay Grimwood
3.76 · 25 ratings
sci-fi · adult · cyberpunk · book · fiction · alternate-history · action-adventure · paranormal · assassins · political-intrigue · christian · historical-fiction · contemporary · dystopia · futuristic · crime · other-world · vampires · life-death · spirituality
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Shifters of the Primus
by Elyssa Ebbott
3.87 · 15 ratings
shapeshifters · adult · sci-fi · paranormal · aliens · fiction · romance · book · steamy · action-adventure · forbidden-love · military · family · genetic-engineering · dystopia · dark · humor · royalty · futuristic
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The Towers of the Earth
by Nita Round
4.30 · 20 ratings
book · adult · magic · historical · fiction · action-adventure · industrial-era · lgbtq · steampunk · wlw · sci-fi · gaslamp · high-fantasy · paranormal · polyamory · romantic-love · alternate-history · female-mc · warriors · outlaws
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Oasis of Filth
by Keith Soares
3.75 · 12 ratings
fiction · zombies · horror · adult · dystopia · post-apocalyptic · apocalyptic · book · monsters · sci-fi · survival · action-adventure · paranormal · literary-fiction · mystery
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ChronoShift
by Zack Mason
3.82 · 11 ratings
time-travel · christian · action-adventure · adult · fiction · historical · spirituality · sci-fi · book · historical-fiction · drama
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Coyote Jones Series
by Suzette Haden Elgin
3.50 · 6 ratings
book · adult · fiction · space-opera · sci-fi · female-author · feminism · mystery · action-adventure · fantasy · female-mc
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