The Doctor and Leela are enjoying a picnic on Shontaa, but their peace is interrupted by a duel to the death between Zygon warlords Anktra and Kestral using a variety of host bodies. The travellers release the Zygons' captives, putting an end to the duel and forcing the Zygons to return their now somewhat angered alien prisoners to their home planets.
- The Zygons assume the forms of a Maakrian swamp-bear, a Tekazoid cave-beast, a Dox barbarian, a Shad'ath gladiator, a Korjan anthropoid, a Polar Modrelian, a tendrak and a valkari.
- The Shonters were one of the comically-named alien races mentioned in the 1975 parodical short film Hallo My Dalek, a parody of the Fourth Doctor era of Doctor Who.
to be added