title: Donald Maclean (spy)
context: From Gresham's, Maclean won a place at Trinity Hall, Cambridge, arriving in 1931 to read modern languages. Even before the end of his first year he began to throw off parental restraints and engage openly in communist agitprop.[3] He also played rugby for his college through the winter of 1932–33.[4] Eventually his ambitions would lead to him joining the Communist Party. In his second year at Cambridge, his father died, afterwards marking a period of parental relaxation. Maclean's political views grew much more apparent in the following years in light of "his admiring, if sometimes puzzled, mother".[5]
question: When did Donald Duart Maclean join the Cambridge Five?
answers: 1931