简介：TheDoctorisanobserverandUNITareprovidingsecuritycoveratanexperimentaldrillingprojectdesignedtopenetratetheEarth'scrustandreleaseapreviously-untappedsourceofenergy,namedStahlman'sGasafteritsdiscoverer.ProfessorStahlmandismissestheconcernsoftheproject'sExecutiveDirectorSirKeithGoldandexceedsallsafetymarginsinordertoexpeditethework. Soonhoweverthedrillheadstartstoleakanoilygreenliquidthattransformsthosewhotouchitintoviciousprimevalcreatureswithacravingforheat.TheDoctorisaccidentallytransportedbythepartially-repairedTARDIScontrolconsoleintoaparalleluniversewhereEnglandisruledbyamilitarydictatorship. Thedrillingprojectisatamoreadvancedstagehereand,thwartedbyhisfriends'ruthlessalteregos,heisunabletopreventthepenetrationoftheEarth'scrust,whichultimatelycausestheplanet'sdestruction.Escapingbacktohisownuniverse,wherethedrillingisstillinprogress,theDoctortriestowarnofimpendingdisaster.Atfirstheisdisbelieved,buthiswordsareborneoutwhenthepower-crazedStahlmanishimselftransformedintooneofthehideousprimordialcreatures. TheDoctor,aidedbyconsultantGregSutton,killsStahlmanwithice-coldblastsfromfireextinguishers.Heisfinallyabletoshutdownthedrillingwithonlymomentstospare.…