 When Cresswell arrived back, Wellington was becoming the focal point of logic in New Zealand. Hughes and Londey had a strong group of graduate students, including Dorothy Grover and Tom Richards. Londey liked to use the English translation of Hilbert and Ackermann’s pre-war Grundzüge der Theoretischen Logik as a text for his advanced course, and in 1965 he and Hughes published their own The Elements of Formal Logic, aimed at undergraduates—Prior reviewed it in the Australasian Journal of Philosophy, describing it as ‘a very good buy’ and ‘broadly in the style of Hilbert and Ackermann, and even more that of von Wright’ (Prior 1966). Also in 1965, Hughes and Cresswell trialled the idea of an undergraduate course in modal logic. The Elements contained no modal logic, and the lack of any suitable textbook for the new course was a problem. ‘We’ll have to write our own’, Hughes said jokingly to Cresswell. Their famous An Introduction to Modal Logic appeared in 1968, overnight turning modal logic from a subject accessible only to experts into one that almost everybody with a bit of logic could understand.