In which Martin Arrowsmith faces an offer to direct the McGurk Institute, confronting the clash between scientific purity and administrative ambition amidst the persistent urgings of his social circle and his wife. Choosing freedom and the simplicity of his work with Terry Wickett in a rustic laboratory, Martin embarks on a rugged yet passionate quest for discovery, even as personal relationships strain and the wider world of culture and science marches inexorably onward.