Episode aired Aug 10, 1968 The TARDIS arrives on the planet Dulkis where the Doctor, Zoe and Jamie decide to have a quiet holiday. Only to find the Evil Dominators and their robotic slaves, The Quarks have arrived on a radioactive island, where they plan to detonate a bomb in the planet's core, which will turn the entire planet as source of radioactive fuel for their invasion fleet.

Jeff Healey: “While My Guitar Gently Weeps” was something we’d wanted to do for the first album. We’d been doing it in our live stage act, playing in bars and so forth, pretty much since we started. I felt two years ago wasn’t a good time to do it, so we didn’t. And it’s just as well because we probably wouldn’t have wound up with the version we have now. So our decision to record it now was a matter of ‘right time, right place’.” “Somewhere through the grapevine he (Harrison) had heard that we were performing “While My Guitar Gently Weeps.” Well obviously, he had to be checked for the rights to record it. So he contacted us and asked whether we wanted any advice or maybe even collaboration. We said: “Sure.” …due to schedule incompatibilities, we had to send the tapes to Los Angeles, where he made a stopover on his way back to London. Jeff Lynne joins him – on his time, thank you very much to Jeff. They went in and recorded their stuff, some backing vocals and acoustic guitar, on the tune. It’s fantastic.” (Guitar World Sept. 1990) “It was good fortune. It began as a little idea and then he expressed some interest in doing it and it just fell together.” (Guitar School Sept. 1990) Ed Stasium: “I spoke with George Harrison, who was in Hawaii at the time, and sent a slave tape to him. We kept eight tracks open, and I sent him instructions – if you want to call it that; “requests” is more like it – that we’d like him to play acoustic and play backup. And that’s what he and Jeff Lynne did – they put their parts down together in L.A. when Lynne was working on his solo record there.” (Guitar World Sept. 1990) Jeff Healey: “George plays acoustic on the song, as does Jeff Lynne. I did all the electric stuff.” (Guitar School Sept. 1990)