Purgatory's Key is a Star Trek: The Original Series novel by Dayton Ward and Kevin Dilmore. It is the third novel in the Legacies trilogy, released on 30 August 2016.


The conclusion to the epic trilogy that stretches from the earliest voyages of the starship Enterprise to Captain Kirk's historic five-year mission—and from one universe to another—just in time for the milestone 50th anniversary of Star Trek: The Original Series!
Eighteen years ago, the starship Enterprise thwarted an alien invasion from another universe, and Captain Robert April took possession of the interdimensional transfer device that made it possible. Since then, each captain of the Enterprise, from Christopher Pike to James T. Kirk, has guarded this secret with his life.
Now, Romulan agents have succeeded in stealing the device and using it to banish Ambassador Sarek and Councillor Gorkon to an unknown realm in the midst of their groundbreaking Federation-Klingon peace negotiations. With time running out as interstellar war looms in one universe—and alien forces marshal in another—will Captain Kirk and his crew preserve the tenuous peace and reclaim the key between the dimensions?


In the other dimension, Sarek and Joanna manage to make contact with Number One and the Enterprise crewmembers sent there eighteen years previous. They, together with the Usildar sent there at the same time and now Gorkon, are engaged in a war with the Jatohr. However, they eventually realise that the world they are perceiving is not physically real to them and their consciousnesses are held elsewhere.

The Enterprise arrives back at Usilde where they make tense but peaceful contact with J'Teglyr, captain of the Klingon vessel overseeing operations on the planet. However, a second ship arrives commanded by Commander Visla, a disgraced officer seeking to regain her honour and avenge Kirk for failing to allow her son an honourable death, attacks the Enterprise without provocation. Her ship is disabled and J'Tegylr takes the survivors aboard.

The Jatohr citadel activates booby-traps that kill most of the Klingon scientists studying it. Having already used the Transfer Key to dispatch a probe to the other realm, Spock and an away team including Amanda beam down to the citadel, which then takes off like a ship and begins attempting to alter Usilde's atmosphere. Eager to prevent this, Spock's team set the Transfer Key to overload. Visla kills J'Teglyr and makes another attempt to attack the Enterprise but is again defeated, and killed by J'Tegylr's first officer.

Spock's team manage to transfer the Jatohr in the other realm to Usilde, then Spock and Amanda mentally contact Sarek and use the link and the probe to send him and the others trapped to Usilde as well, before being beamed off the citadel just before it explodes. With matters concluded peacefully with the Klingons, the Federation set about relocating the Jatohr and repairing the environmental damage to the Usildar's world. With the purpose of the Transfer Key fulfilled, Kirk concludes that he is satisfied with the end of that particular legacy, as for him the legacy of the Enterprise should be a focus on their mission of exploration and expanding knowledge rather than keeping secrets.



USS Enterprise personnelEdit

Pavel ChekovBarry GiottoHawthorneJames T. KirkLeonard McCoyMichael MedeirosNick MinecciElizabeth PalmerNaomi RahdaMontgomery ScottSpockHikaru SuluNyota UhuraValren
Referenced only 
Christine ChapelJabilo M'Benga

Other Starfleet personnelEdit

Thomas BlairJames Cambias • Dylan Craig • Bruce GoldbergKaren GriffinIngrid HolstineTerra Le MayRaul MartinezTim ShimizuCheryl StevensUna
Referenced only 
Robert AprilPeder CossEnwrightJane HamiltonJames KomackChristopher PikeRobert Wesley

IKS Qo'Daqh personnelEdit


IKS Vron'joQ personnelEdit


Klingon contingent on UsildeEdit



Referenced only 



Other charactersEdit

GorkonAmanda Grayson • Joanna McCoySarekBeel Zeroh
Referenced only 
AyelbourneHudekK'tovelKovorKrasM'RekLeightonNettPektu-KeltzPrangSadira/Lisa Bates • SkonToqVrax

Starships and vehiclesEdit

antigrav skidantigrav sledUSS Defiant (Constitution-classUSS Enterprise (Constitution-class) • IKS Qo'Daqh (D5-class) • IKS Vron'joQ (D6-class)
Referenced only 
IKS D'ghajIKS HoS'lethUSS Lexington (Constitution-class) • USS MasaoNomadUSS Potemkin (Constitution-class) • ChR VeliborUSS Yorktown (Constitution-class)


Libros systemUsilde (Jatohr citadel)
Referenced only 
Capella IVCentaurus (New AthensNew Athens University Hospital) • Chipewa PrimeEarth (Starfleet Headquarters) • IllyriaGre'thorMirror UniverseQo'noS (First CityKintak) • Starbase 6Sto-Vo-KorTalos IVVulcan (Fire PlainsRaalVoroth Sea)

Races and culturesEdit

Human (Indian) • IllyrianIzarianJatohrKlingon (QuchHa') • UsildarVulcan
Referenced only 

States and organizationsEdit

Klingon Defense ForceKlingon EmpireKlingon High CouncilStarfleetUnited Federation of Planets
Referenced only 
Imperial AcademyKlingon High CommandNew Athens UniversityRomulan SenateRomulan Star EmpireStarfleet AcademyStarfleet CommandStarfleet Corps of EngineersStarfleet IntelligenceStarfleet MedicalVulcan Science Academy

Science and technologyEdit

acquisition sensoralgorithmamplifier screenannular confinement beamanti-Keyartificial gravityasphyxiationastrogatoratmospherebatterybinary systemcardiac arrestcarrier wavecatatoniachronometercloaking devicecommunicationscommunications arraycommunicatordampening fielddata carddata slatedeflector shielddisruptorelectromagnetic spectrumFeinberg receiverfood slotfrequencygamma radiationgastropodharmonicshydrogenimpulse engineinertial dampenerintrusion control barrierion stormionized plasmalife supportmatter streammatter-antimatter integratormemory coremesosphereminingmolecular harmonicsnacellenavigational deflectornitrogenoptical data network relayphaserphoton torpedophysicsplasmaplasma conduitpower generatorpredictive tracking screenprobepulsing lightradioscannerscattering fieldsensorsensor arraysentry globeshield generatorsubspace carrier wavesubspace communicationsTantalus fieldterraforming, thermoconcrete, thoughtspaceTransfer Keytransfer-field generatortransfusiontransportertricorderwarp drivewarp factorxenobiology

Ranks and titlesEdit

admiraladviseragentambassadorartisanattachécadetcaptainchief engineerchief medical officercommandercommodorecommunications officercomputer techniciancouncillorcrewmanensignfirst officergeneralhelmsmanHigh Masterinstructorlieutenantlieutenant commanderofficernavigatornursepetty officerPraetor of the Romulan Star Empirequartermasterrangerscientistsecurity chiefsensor officersoldiertactical officerwarriorweapons officerxenobiologistyeoman

Other referencesEdit

amputationBabel conferencebaldricbat'lethbathrobebirdbrigcanechessclubcoffeecommendationcourtyardd'k tahgdesertdormitoryEarth-Romulan WarEartherespionagefarmfireflowerforestgladegrasshelmethobgoblinhospitalinsectinternment campJefferies tubeKol-ut-Shankrenchalabor camplagoonlakelanternlavaleaflivestockmeditationmedkitmevmind meldmountainOrganian Peace TreatypetaQpujqI'ragrobesalt plainsand-firesatchelSaurian brandyseed shellShevok'tah gishshrubsleeper holdspearstaffStarfleet General Orders and Regulationsstone survival kittargtlhIngan HoltourniquettowelTreaty of Algerontreetree branchVulcan nerve pinchwind



Published Order
Previous novel:
Best Defense
TOS novel Next novel:
The Face of the Unknown
Previous story:
All That's Left
Stories by:
Dayton Ward
Next story:
The Menace of the Mechanitrons
Previous story:
All That's Left
Stories by:
Kevin Dilmore
Next story:
The Menace of the Mechanitrons

External linkEdit

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