Original air date May – June 1964
Ian, Barbara, Susan, and The Doctor land in South America at the height of Aztec culture. They emerge from a one-way door – leaving the TARDIS behind it – in a temple, which only reincarnated gods can use. Barbara, particularly, is treated as the incarnation of the goddess Ytaxa. This works fine until her 1960’s sensibilites get involved and she tries to stop human sacrifice. Meanwhile, the Doctor absent-mindely gets engaged to a local wise woman (they are a lovely couple!). They all scheme to get back to the TARDIS.