Two on a Tower Chapter 4

In which Lady Constantine visits the solitary astronomer Swithin St. Cleeve atop the Rings-Hill column on a clear starlit night, where he passionately reveals to her the vast and terrible immensity of the cosmos through his telescope. In the midst of their celestial discourse, she entrusts him with a confidential and urgent personal errand concerning her husband, which he agrees to undertake on condition that she watch over his delicate astronomical observations in his absence.