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简介：TheTARDISmaterialisesinahostilejungleontheplanetSpiridon.JosetsoutalonetofindhelpfortheDoctor,whohasfallenintoacoma.ShemeetsapartyofThalsandisleftinhidingaboardtheircrashedspaceshipwhiletheygototheDoctor'said.TheTimeLord,nowrecovered,learnsoftheirmissiontodestroyapartyofDalekssentheretodiscoverthenativeSpiridons'secretofinvisibility. AnotherThalspaceshipcrash-landsinthejungle,andthesurvivorsbringnewsthatsomewhereonSpiridonthereisanarmyoftenthousandDaleks.JomeanwhilemeetsafriendlySpiridonnamedWester,whocuresadeadlyfungusdiseasethatshehascontracted. IttranspiresthattheDaleks'armyisfrozeninsuspendedanimationinacavernbelowtheirbase.TheDoctor,withthehelpoftheThals,explodesabombinthecavernwallandtherebycausesoneoftheplanet'snaturalicevolcanoestoerupt,entombingthearmyinatorrentofliquidice. Thenewly-arrivedDalekSupremeandhisaidesareleftstrandedonSpiridonastheThalsstealtheirshipandtheDoctorandJodepartintheTARDIS.…