In 1879 Lopatin returned clandestinely to Russia to work with 'Land and Liberty'. When that organisation split the same year, Lopatin sided with 'The People's Will'. However, he was arrested again. In 1883 he escaped from Siberia once more and returned to the West. In Paris he collaborated with Lavrov and other exiles in reviving 'The People's Will', trying to convert it from a Blanquist conspiratorial organisation into a mass party and arguing that the party should seek to organise the emerging industrial proletariat. Lopatin became a member of the party's Administrative Committee and served as its de facto leader. He was instrumental in unmasking the secret police agent S.P. Degaev.
